Tag: Cell Biology

A recent paper by Scheuring and colleagues investigates vacuole biogenesis in meristematic cells of Arabidopsis thaliana, challenging earlier models of vacuole formation. Vacuoles are crucial organelles responsible for various cellular functions, yet their formation has remained puzzling for quite some…

Numerous studies have highlighted the critical importance of plasma membrane heterogeneities in regulating cell functions, leading to a proliferation of overlapping and contradictory terminologies. Here, Jaillais and others in the field propose a new system of nomenclature. It really is a must-read for…

In mesophyll cells, carbonic anhydrase is mainly located in the chloroplast, however it is in the cytosol in plants with a C4 carbon concentrating mechanism. There is interest in relocating carbonic anhydrase to the cytosol of C3 plants as a first step in the introduction of a carbon concentrating mechanism.…

Plants rely on an array of mineral nutrients for their growth, development, and reproductive processes. The molecular mechanisms governing the uptake, translocation, storage, and utilization of these essential minerals are orchestrated by specific nutrient transporters and their associated regulatory…

Plants adapt to salt stress by maintaining ion balance using ion transporters. While much is known about cation transporters, the role of anion transporters is less clear. Rajappa et al. focus on the chloride channel gene AtCLCf in Arabidopsis thaliana, controlled by the transcription factor WRKY9 under…

ATG8 is a well-characterized protein involved in autophagy that binds to the double-membrane enclosed phagophore. In a new preprint, Julian et al. explore their finding that ATG8 binds to the single-membrane enclosed vacuolar membrane (tonoplast). They observed that this binding is enhanced by treatments…

Transporting cargo within a cell may seem straightforward, but it is actually an intricate task. At the plasma membrane in plant cells, this complexity is navigated by a process known as clathrin-mediated endocytosis. Central to this process are two key players: adapter protein AP-2 and the TSET/TPLATE…

Fifty years ago (1974), Albert Claude, Christian de Duve, and George Palade were awarded the Nobel Prize for their discoveries on the structural and functional organization of the cell, which Claude eloquently framed by writing, “We have entered the cell, the mansion of our birth, and started the inventory…

The exocyst complex is a conserved octameric protein complex in eukaryotic cells. Its primary function is to tether secretory vesicles to the plasma membrane during the exocytosis process, and it is also involved in autophagy and host-pathogen interactions. Intriguingly, EXO70, one of the subunits of…

In angiosperms, pollen germination leads to a period of extensive polarized growth of the pollen tube, which carries the sperm nuclei to the ovule. Studies of tip growth in both pollen tubes and root hairs have contributed to a descriptive model that involves polarized vesicle movement along the cytoskeleton…

Microtubule binding proteins are important in determining fruit shape by driving changes in microtubule arrangement. However, in depth molecular studies on these in tomato (Solanum lycopersicum) have been limited. Here, Bao et al. investigated the microtubule binding protein Microtubule-Associated Protein…

I highly recommend this excellent and accessible article by Borg et al. that provides an overview of the red macroalgae, which “may have been the first eukaryotic lineage to have evolved complex multicellularity”. It’s full of fascinating information: although 97% of red algal species are marine,…

The September issue of Plant Physiology has a focus on plant cell polarity, which plays a pivotal role in the fundamental processes that dictate plant growth, development, and adaptation. By establishing distinct regions within cells, plant cell polarity is crucial for regulating asymmetric cell divisions,…

Cellulose in one of the most abundant polymers on the planet and is synthesized by plasma membrane-bound cellulose synthases (CESAs). Phosphorylation plays a role in CESA regulation, however the kinases which catalyse the phosphorylation are not well described. Here Xin et al. identified calcium-dependent…

In plants, gravity sensing is orchestrated by specialized cells called statocytes that contain starch-filled plastids (amyloplasts) called statoliths, whose positions are influenced by the direction of gravity. However, the molecular mechanisms of gravity sensing and signaling are poorly understood.…

Phosphoinositides (membrane lipids with cytosolic inositol headgroups carrying phosphate residues at various positions) serve as road markings for membrane and membrane/cytoskeleton dynamics. Here, Lebeco et al. add further detail to the map. Previously the authors showed that the plant-specific enzyme…

Although The Plant Cell Focus Issue on Biomolecular Condensates officially comes out in September, due to the idiosyncrasies of publishing many of the articles are already available online, and I’m highlighting them now because this topic is also the focus of a plenary session at the Plant Biology…

Precise spatial control of cell division and cell growth is necessary to produce the specific cellular organizations demanded by the complex tissues and organs of morphologically complex organisms One of many factors that guide cell division/growth is cell polarity, of which RHO GTPase-type proteins…

Biomolecular condensates are non-membrane-bound compartments containing proteins and RNAs with key functions in stress responses. In plants, they occur as several types with different properties and components, including stress granules and processing bodies. Protein domains such as prion-like domains…

Chloroplasts divide by binary fission driven by a protein ring, the position of which is regulated by the Min system (derived from the system in bacteria). The inner envelope membrane protein PARC6 (PARALOG OF ARC6) is a key component. Here Sun et al. generated crystal structures showing that PARC6 interacts…

Bending or folding in plants is influenced by different factors such as environmental conditions (nutrient, water, light, gravity), abiotic or biotic stress, cell wall properties, and cell differential growth. Jonsson et al. explain how bending is achieved by considering molecular mechanisms, mathematical…

Lately, reactive oxygen species (ROS) have been recognized as signaling molecules that regulate plant cellular proliferation and differentiation in many areas of the plant, including root tips. Chloroplasts, peroxisomes, and mitochondria are the main cellular compartments for ROS generation in cells.…

Cellulose synthase (CESA) complexes (CSCs) synthesize the main polysaccharide component of plant primary cell wall, cellulose. The trafficking and dynamics of CSC are tightly regulated. Kesten et al. identified a new family of CSC- and microtubule-interacting proteins, named TETRATRICOPEPTIDE THIOREDOXIN-LIKE…

Salt is a massive problem for most land plants. At the macroscopic level, excess soil salinity can cause stunting or death. At the molecular / cellular level, salinity causes both osmotic and ionic challenges that affect membrane homeostasis, molecular interactions, and protein stability. A new review…

Some of the most fascinating questions in biology, subject to numerous Nobel Prizes, center on how all the parts of a eukaryotic cell are spatially and temporally coordinated, to allow the plethora of often incompatible functions to occur in harmony. Studies in three major systems, yeast, metazoans,…

The plasma membrane (PM) is a critical interface between the cell and its environment and serves crucial sensing and transducing roles. This timely review by Medina-Puche and Lozano-Durán updates exciting new developments in understanding communication between the PM and intracellular organelles, focusing…

In a contribution to the January 2022 Plant Cell Focus Issue on Plant Cell Biology, Kang et al. have assembled an updated survey of plant cell structures. This review includes a dozen mini-reviews that describe various compartments or structures within plant cells: the nucleus, endoplasmic reticulum,…

Have you noticed that the quality and resolution of cell images has been getting better and better? Weiner et al. review the recent advances in 3D electron microscopy (EM) technologies that have provided these strikingly beautiful and informative images. Like “classic” transmission EM, EM tomography…

As part of The Plant Cell’s upcoming celebration of plant cell biology, Roeder et al. write about fifteen of the “open questions” in the field. This, and the other reviews that make up the focus issue, provide valuable insights into the leading edge of the discipline. Among the questions posed:…

The development of Arabidopsis as a model system greatly advanced the field of plant cell biology by bringing in molecular approaches, so much of our conceptual foundation rests on studies from angiosperms. More recently, model bryophytes, particularly Marchantia polymorpha (liverworts) and Physcomitrium…

Manuel Mora (he/him) is a doctoral student in the Molecular Biology Interdepartmental Developmental Program (MBIDP)  at UCLA. Born in Santa Ana, CA, Manuel was raised between California and the town of Santiago Tangamandapio in Michoacan, Mexico. Growing up he enjoyed playing soccer, but when living…

The ability to perceive and respond to mechanical stimuli and forces, such as gravity or touch, is an extremely well conserved property that is key for proper cellular function. This ability is fueled by mechanosensitive ion channels activated by mechanical disturbances in the membrane, which leads to…

A plant has many layers of defense against a pathogen. One of the first challenges a pathogen faces is how to get inside the plant. Some bacteria sneak in through open stomatal pores, and some fungi form high-pressure appressoria that burst through walls. Here, Bronkhorst et al. investigated how the…

The question “Are plants intelligent?” is raised regularly, with answer often “Well, it depends how you define intelligence.” Another interesting question is whether or not plants have cellular structures that are analogous to those that make up the animal nervous system. Robinson and Draguhn…

Plants demonstrate a gorgeous diversity in cell types to adapt to their unique environments. Certain cell types, such as the epidermal, cortex, and vascular cells within plant roots, or the classically-defined root developmental zones (meristematic, elongation, and maturation), are homologous in angiosperms.…

Calcium (Ca2+) signaling regulates a host of stress and developmental responses in plants. Apart from increases in cytosolic Ca2+ concentration ([Ca2+]Cyt.), organellar signals play a key role in shaping the cytosolic signaling events. In an attempt to understand the Ca2+ dynamics in the endoplasmic…

Plasmodesmata, the tubular connections that form continua between neighboring cells in plants, play vital roles in long-distance transport of ions, RNA, proteins, and small molecules. While it is known that plasmodesmata are permeable to phytohormones, including auxin, the physiological significance…

Understanding cellular responses to the phytohormone auxin has always been a challenge and decades of work has constantly renewed our knowledge of the same. Here, Narasimhan and colleagues attempted to revisit and resolve the basis of differential action of naturally occurring auxin indole-3-acetic acid…

Gamma-aminobutyric acid (GABA) is a non-protein amino acid produced by animals and plants, but is its function conserved across kingdoms? In mammals, GABA acts as chemical messenger in the central nervous system by inhibiting neurotransmission. In plants, GABA accumulates in response to stress but its…

Autophagy is an intracellular evolutionarily conserved catabolic process that degrades cytoplasmic constituents and organelles in lytic vacuoles (micro- and macro-autophagy) or in the cytosol (mega-autophagy). Autophagy can be induced by biotic or abiotic stresses, sugar, carbon and nutrient starvation…

Mitochondria function as cellular powerhouses to generate energy via oxidative phosphorylation and facilitate the synthesis of essential macromolecules. To protect against proteotoxic stress, damaged mitochondria are selectively removed by autophagy via a process known as mitophagy. In mammalian cells,…

The exocyst is a conserved protein complex that mediates tethering of secretory vesicle to the plasma membrane prior to SNARE-mediated membrane fusion. Exo70 is one of eight subunits and has expanded into 23 homologs in Arabidopsis. Brillada and Teh et al. identified Exo70B2 as a bona fide exocyst subunit…

The ability to utilize stored energy is crucial for organism growth and development. For example, seed storage lipids go through hydrolysis and beta-oxidation to provide energy for seed germination. In this process, beta-oxidation occurs in the peroxisome, a subcellular compartment that houses many…

Review: Organelles-nucleus-plasmodesmata signaling, and roles in plant physiology, metabolism and stress responses Plasmodesmata (PD) are pores that connect plant cells and allow the flow of small molecules and information but also viruses. This traffic is tightly regulated, in large part by the deposition…

Review: Emerging roles of long noncoding RNAs in the cytoplasmic milieu Note: This article focuses on work in mammalian systems but may be of interest to plant biologists. Long non-coding RNA (lncRNAs) are ³200nt RNAs and represent almost 0.2% of cellular RNA pool. Early work focused on their roles…

Cell wall remodeling and vesicle trafficking mediate the root clock in Arabidopsis Living organisms use biological clocks that are coordinated by temporal signals (time) and positional cues (space) during growth and development. In plants, the ‘root clock’ is generated by a mechanism involving…

Many people are familiar with the popular houseplant Cephalocereus senilis, which also known as old man cactus because it is covered with long white hairs that are thought to protect it from frost and UV light. A similar function is described for the wooly fibers that cover the alpine plant Dionysia…

The trans-Golgi networks (TGN) is a major protein sorting station involved in trafficking or recycling of endosomal materials. This busiest hub in the cell has at least four important pathways including the anterograde routes of secretory, recycling, vacuolar transport and retrograde endocytic pathways.…

Cis-regulatory elements (CREs) are DNA sequences found near or within genic regions that drive proper gene expression in time and space. Thus, CREs play essential roles in the diversification of spatially distinct cell-types with specialized function in multicellular organisms. To identify CREs underlying…

Polar cell growth is a key feature in plant organs like root hairs, trichomes and pollen tubes. Kulich and co-workers have identified novel regulatory elements governing the polar growth of root hairs and trichomes in Arabidopsis thaliana. Studying a group of proteins named ARMADILLO REPEAT ONLY (ARO),…

Asymmetric cell divisions (ACDs) are often used by organisms to generate different cell sizes, each adopting a different cell fate. In plants, stomatal development provides an example of an ACD-derived patterning mechanism. Several proteins are known to be implicated in ACDs, like BREAKING OF ASYMMETRY…

Proteins’ sub-cellular localizations provide a wealth of information regarding their functional attributes. Protein localization in plant cells is usually done through genetically combining fluorescent proteins to the protein-of-interest. Now, Iwatate and colleagues report the successful localization…

The cell cycle requires a series of transitions from G1 to S, S to G2, G2 to M and M to G1 phases. Determining the cell cycle phase is critical for understanding the molecular events specific to a given stage of cell cycle. However, markers for identifying these cell cycle transitions in plants are not…

Biomolecular condensates are membraneless organelles with the capacity to spatially concentrate biomolecules. Liquid-liquid phase separation (LLPS) is one mechanism of condensate formation in which demixing of macromolecules leads to separation into dense and light phases. Photosynthetic organisms like…

Rho-of-plants (ROP) proteins are master regulators of cell polarity within plants and influence cell wall deposition, tissue development, and several signaling processes. However, they are quite difficult to study: attempts to form a fluorescent ROP fusion protein have proven elusive, and there are multiple…

Quality control of the protein folding mechanism in the endoplasmic reticulum (ER), which selectively eliminates or recycles unwanted cytoplasmic components, is recognized by specific autophagy receptors. Selective removal of certain ER domains by the autophagy pathway (termed as ER-phagy) is controlled…

Many proteins polarize in the cell creating a subcellular niche for various functions. Asymmetric distribution of proteins is a general mechanism for localized growth, directional long-range signaling, cell migration, and asymmetric cell divisions. Well-known examples of polarity proteins include PIN-FORMED1…

Roots are essential organs for nutrient and water uptake and have been extensively investigated in angiosperms. Many studies suggest that roots originated through convergent evolution in vascular plants, a clade that includes seed plants and ferns. Besides Arabidopsis and crops, little is known about…

During heat stress, heat shock transcription factors upregulate heat shock protein genes and give rise to the heat shock response (HSR) that occurs in the cytoplasm, while in the endoplasmic reticulum (ER), the unfolded protein response (UPR) is also activated during heat stress. Both HSR and UPR cause…

Chloroplasts are involved in various plant cell functions outside of photosynthesis including defense activation. How is the chloroplast able to do so? In this study, Medina-Puche et al. characterized the molecular function and cellular localization of the Tomato yellow leaf curl virus-derived C4 protein.…

Many plants take advantage of microbial symbionts to boost their nutrient uptake, with classic examples provided by mycorrhizal fungi and the legume/Rhizobia partnership. Similar symbiotic partners are found in other domains of life, including the coral/dinoflagellate symbiosis, and the symbiosis…

Plant seeds can remain dormant for several years under stress conditions and subsequently germinate once favorable conditions return. Even though this phenomenon has been known for many years, what keeps the seed from germinating during the unfavorable conditions, especially during water deficit conditions,…

Protein degradation is mediated by several systems: the ubiquitin-proteasome system, multi-vesicle body-mediated vacuolar sorting (MVB), and the autophagy-vacuole pathway. However, the communication between these different protein degradation systems are less characterized. Here, Xia et al. report a…

Biological processes are ruled by physical as well as chemical forces and properties, but the former are much less well understood and studied. Here, Michels et al. describe a collection of fluorescent probes that provide a quantitative visual readout of microviscocity, reflecting the physical properties…

Plant development is a regulated process of cell division, expansion, and differentiation. Membrane lipids are crucial to these processes, as illustrated in this review by Boutté and Jaillais. The authors discuss the major lipid components in the different membrane systems and how these vary in space…

Small signaling peptides are cleaved from precursor proteins by the action of proteases and are also subject to other post-translational modifications. Subtilases (SBT) are mostly extracellular proteases, but SBT6.1 is membrane-localized at the Golgi and plasma membranes. Furthermore, it has been shown…

Moving materials within and out of cells requires that membranes carry identification labels, but when the membrane itself moves, that ID label must be updated. These requirements are met ingeniously by the anionic lipids, which are both a modifiable information system and simultaneously modify the physicochemical…

Phytophthora are plant-destroying oomycetes. Within this genus are several infamous disease-causing agents: P. infestans of the potato late-blight fame, P. sojae of soybean root rot, P. ramorum of sudden oak death, and many other lesser-known species. This fine new review by Boevink et al. explores the…

Intrinsically disordered proteins (IDP) have repetitive protein sequences but lack a defined 3D structure and are deployed to do some challenging functions that a protein with a defined 3D structure cannot perform. One such IDP, Oryza sativa REPETITIVE PROLINE-RICH PROTEIN (OsRePRP) is involved in inhibiting…

The nucleus is an organelle with tremendous shape flexibility in response to environmental cues; it has been described as the “plastic, elastic, and fantastic” organelle. The change in nuclear geometry based on mechanical stress is well documented from single cell studies in culture, but the question…

In this paper, Moreno et al. investigate how nitrate affects the balance between cell proliferation and cell expansion in shoots during early seedling development. They note that the cells in Arabidopsis cotyledons undergo considerable enlargement, and that the increase in cell size is correlated with…

Genome duplications are common in plants and thought to be an important contributor to evolutionary innovations, but the increase in ploidy that results from a genome duplication also presents challenges for reproduction. Because there are four sets of homologous chromosomes in the derived tetraploid…

The thylakoid membranes are located in the stroma of chloroplasts and house the machinery for the photosynthetic light reactions. They emerge largely de novo during the transition from pro-plastids into mature, photosynthesizing chloroplasts. Generating new thylakoid membranes requires a supply of lipids,…

Plant cells are known to initiate local and systemic signaling in response to certain stressful conditions to safeguard cells in the immediate vicinity as well as that are far from the site of stimuli. In this study, Cheval and co-workers have characterized a pathway in plant cells for sensing and responding…

Parasitic plants develop unique structures called haustoria that penetrate into the host plant vasculature, from which they take nutrients. During this process, haustorial epidermal cells differentiate into specialized cells called intrusive cells, which eventually re-differentiate into a xylem bridge…

Some “superfoods” have high nutritional value due to the presence of carotenoids, which prevent degenerative diseases like cancer. In plants, these pigments are biosynthesized and stored by plastid organelles called chromoplasts. Chromoplast number and size define total carotenoid accumulation. ORHis,…

Plant grafting is an agricultural technique that joins plant tissues (e.g., the shoot and root) to confer beneficial traits from one plant to another. Although interfamily grafting is difficult in general, Notaguchi et al. found that Nicotiana benthamiana (Nb) has a strong potential to graft with phylogenetically…

Much remains to be learned about the sensing and signaling mechanisms controlling growth in response to drought. To dissect how plants control drought via autophagy, Bao et al. found a plant-specific protein, COST1 (CONSTITUTIVELY STRESSED 1) containing a DUF641 (domain of unknown function 641) domain,…

In flowering plants, fertilization occurs when a pollen tube, growing down the transmitting tissue, arrives at the ovule, ruptures, and releases its content of sperm cells. The pollen tube is guided towards the ovule by LUREs, small cysteine-rich secreted peptides. Timely rupturing and sperm release…

In multicellular organisms like plants, asymmetric cell division can arise from cell polarity. The signals that establish cell polarity relative to the body axis are unknown in plants. In Arabidopsis, SOSEK1 was previously identified as having a polar distribution. SOSEK1 has a DIX domain similar to…

Storage proteins secreted into vacuoles during seed development serve as precursors for germination and plant growth. In this paper, Ren et al. identified a regulator, GLUTELIN PRECURSOR ACCUMULATION 5 (GPA5) that is involved in protein trafficking into the vacuoles during seed development. The loss…

While cell division and cell expansion are known to be determinants of plant organ growth, little is known about the role of cell elimination and death in this process. Cell death indicators such as cell death- and autolysis-associated cysteine proteases have been observed in cells overlying the site…

We have only recently begun to appreciate the phenomenon of cross-species or cross-kingdom small RNA transfer, and its applications. Using examples from plants and animals, Cai et al. summarize how some pathogens have evolved the capacity to introduce small RNAs into their host to suppress host defense…

Organelles, such as the chloroplast and nucleus, are structures with specific functions within a plant cell. It has been reported that many related, or homologous, proteins function in different organelles. However, how and why organellar proteins have diverged over evolutionary time remains unclear.…

How do cells know when it is time to divide? Helt et al. explore this question using the single-celled alga Chlamydomonas. Unlike most animal and fungal cells, which tend to maintain a relatively consistent size by dividing after their size has doubled, Chlamydomonas cells can undergo several rounds…

During cell division, cells require to form mitotic spindle and these mitotic spindles are basically newly formed microtubules. The formation of new microtubules depends on γ-tubulin. Along with 5 GPCs (γ-tubulin protein complex), γ-tubulin form γTuRC (γ-tubulin ring complex) and it facilitates…

Orientation of cell division decides daughter cell fate and is fundamentally important for tissue patterning and morphology. For instance, asymmetric cell division leads to the generation of new cell types; in contrast, symmetric division produces cells with similar identity in a proliferative manner.…

Ample evidence shows that rather than being homogenous, plasma membrane lipids and proteins form distinct nanodomains. Jallais and Ott review plant plasma membrane nanodomains, and their important contributions to receptor-mediated signaling. The authors discuss methods for the study of membrane nanodomains,…

As their name suggests, phosphoinositide (PI) phosphatases remove phosphates from phosphoinositides (try saying that fast!). Because the phosphorylation status of a membrane-bound PI determines which proteins it interacts with, PI phosphatases and kinases contribute to membrane functions and dynamics.…

Phosphoinositides (PIs) are specialized membrane lipids that contribute to membrane nanodomains, which affect protein localizations and vesicle trafficking. Previous studies have implicated PIs in the polar localization of auxin-transporter PIN proteins, and, in roots, the PIN-regulators PAX and BRX.…

In the middle part of the 20th century, cell biology leapt forward with the development of differential centrifugation methods for purifying subcellular compartments. However, these methods require large amounts of starting material and can suffer from contamination. Kuhnert et al. present a new simple…

The ability of seeds to pack nutrients into dense stable capsules transformed plants’ and animals’ ability to thrive on land (imagine getting through your day without eating any foods derived from seeds or animals that eat seeds). Within many seeds, nutrients are packaged in lipid droplets, with…

A new review by Petit et al. skillfully highlights the role of plasmodesmata at the interface between cell biology and whole-plant physiology. These tiny channels that connect plant cells determine what moves from cell-to-cell symplastically, so have roles in just about everything, from developmental…

Plasmodesmata are tiny regulated channels that connect adjacent plant cells through which nutrients, signaling molecules and viruses can move. To try to resolve discrepancies between functional and structural studies, Deinum et al. have developed a model for plasmodesmatal permeability that predicts…

Plants have evolved with rooting cells to anchor them to the land and uptake nutrients efficiently. Growth of root hairs in seed plants or rhizoids in early diverging plants both rely on tip growth, which requires a coordination of wall loosening and deposition of wall materials with cell expansion in…

Ren et al. examine the structure of maize pollen actin. Plant Cell https://doi.org/10.1105/tpc.18.00973 Zhanhong Ren (Ph.D. candidate), Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Center for Biological Science and Technology, College of Life Sciences, Beijing…

Multicellularity has arisen independently many times across the eukaryotic tree of life (e.g., in plants, animals and fungi). Comparisons of green algae with land plants is likely to identify the genetic toolkit of multicellularity as well as the colonization of terrestrial habitats. Here, Liang et al.…

Plasmodesmata, small cytoplasmic channels connecting adjacent cells, allow small molecules to move and redistribute information and resources. Plasmodesmatal aperture is highly regulated, which is crucial to development and defense. Hernández-Hernández et al. review the contribution of turgor pressure…

Magnaporthe oryzae, the causal organism of blast disease in rice and wheat, is the most devasting pathogen in rice production. During infection, it develops a germ tube that forms an infection structure called the appressorium. Through septin-mediated reorganization of the cytoskeleton, a high amount…

Plants can regenerate organs after damage, or even regenerate a whole plant. The regeneration efficiency is different across the organism. In this study, Durgaprasad et al. studied the factors that determine regeneration competence across Arabidopsis roots. They focussed on PLETHORA2 (PLT2), a gene involved…

Autophagy is a recycling pathway that supports numerous processes, from nutrient remobilization to abiotic and biotic stress responses. Dauphinee, Cardoso et al. have developed a multi-step pathway that allows them to screen for inhibitors of autophagy in order to build a repertoire of new tools. For…

In Arabidopsis thaliana, changes in day-length (photoperiod) activate the expression and transport of phloem-mobile florigen (FT, FLOWERING LOCUS T) to the shoot apical meristem to trigger the transition to flowering. While the role of FT as a long-distance signal is well-established, the underlying…

Phospholipase D (PLD) enzymes cleave phosopholipds to release phosphatidic acid (PA), which is a signal that affects membrane dynamics. Previous studies have indicated a role for PLD and PA in root responses to osmotic and salt stress, but as the Arabidopsis genome has 12 genes encoding PLD questions…

In most eukaryotic algae, carbon fixation takes place in an organelle within an organelle, the pyrenoid inside of the chloroplast. Besides being functionally very important, pyrenoids are interesting because they are what is called a phase-separated structure, that is they are not membrane enclosed;…

Membranes have long been considered somewhat inert materials in a cell’s organization, but it is becoming clear that lipid composition and distribution contributes actively to cell shape and dynamics. Pan et al. examined the contribution of lipids to the shape of epidermal pavement cells in Arabidopsis…

To balance water loss and CO2 assimilation, stomatal aperture is tightly controlled in accordance with environmental changes, mediated by ABA signaling. Here, García-León et al. found that ABA sensitivity and stomatal aperture are regulated by the trafficking and vacuolar degradation of ABA receptors…

Symmetric cell division leads to proliferation, and asymmetric cell division establishes differential growth. Formation of lateral roots (LRs) depends on asymmetric division of initially symmetric founder cells. Barro et al. studied the mechanism of asymmetric radial expansion by analyzing cytoskeleton…

Vanhaelewyn et al. examine phototropism in adult plants. Plant Cell https://doi.org/10.1105/tpc.18.00929 By Lucas Vanhaelewyn1, András Viczián2, Filip Vandenbussche1 Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, KL Ledeganckstraat 35,…

Soil salinity is one of the most important global problems that negatively affect crop productivity. Jiang et al designed a forward genetic screen in A. thaliana to identify the specific ionic response triggered by salt stress. They mutagenized plants expressing the genetically encoded Ca2+ sensor aequorin,…

Xylem is involved in the movement of water and mineral nutrients through the plants from the roots to leaves; its cells are not totipotent and undergo programmed cell death. VASCULAR-RELATED NAC-DOMAIN (VND) transcription factors are master switches of xylem cell differentiation in Arabidopsis and much…

Plasmodesmata are channels through the cell wall that allow molecules and substances to move back and forth as needed; they also play a central role in growth, development and defence of all higher plants. In this study, Grison et al. describe the rapid relocation to the plasmodesmata pores of two plasma…

SCHENGEN 3 [SGN3, also known as GASSHO1 (GSO1)] is a leucine-rich repeat receptor kinase (LRR-RK) previously shown to interact with CIF peptides (CASPARIAN STRIP INTEGRITY FACTORS) to regulate the development of the Casparian strip boundary in roots. Here, Okuda et al. characterize the CIF/LRR-RK interaction.…

The angle at which roots grow into the soil is modulated by the interaction between genetics and environment, and involves the gravity perception and response pathways including auxin transporters. Ogura et al. did a GWAS analysis of the gravitropic response of different Arabidopsis accessions in…

Osmotic stress in plants elicits many responses, one of which is increased accumulation of Ca2+ in the cytosol. Genes involved in this response have been identified, yet the mechanism behind the Ca2+ transport remains unknown. Maity et al. investigated the structure and function of the osmolality-sensitive…

Regulation of gene expression at transcriptional, translational and post-translation levels is crucial for proper plant growth. Post-transcriptional gene regulation by small RNAs like microRNA (miRNA), siRNA and phasi-RNAs is necessary for meristem maintenance in plants. Unlike in the mammalian system,…

Clamydomonas reinhardtii is the most thoroughly characterized unicellular alga. Like yeast, it is a single-celled eukaryotic organism that is easy to culture, and it lives predominantly in its haploid form but is readily mated for genetic studies. Additionally, it is light-responsive,  photosynthetic,…

Root hairs vastly increase the surface area of the root in contact with the soil substrate, and are crucial for efficient water and nutrient uptake. They are also an excellent system for studies of polar growth or tip growth in cells, a process that involves the cytoskeleton, defined membrane domains,…

The rate of most biological processes is ultimately determined by protein activity levels, which of course are determined by rate of degradation or inactivation as well as production. Dissmeyer reviews the Cys/Arg branch of the N-degron pathway (previously called the N-end rule pathway) that contributes…

Interactions between plants and microorganisms occur in many different ways and on many different levels. Scientists have been attracted to this field of research because of the need to identify the agents causing infectious diseases in economically important crops. Models have been developed to describe…

Transport protein particles (TRAPPs) are multisubunit complexes that regulate intracellular trafficking, but haven’t yet been well characterized in plant cells. The authors previously identified AtTRAPPC11 as an abundant protein in the SYP61 vesicle proteome, with homology to mammalian TRAPPC11. Here,…

Trichomes (plant hairs), arise from epidermal cells of plants. The molecular mechanism involved in the development of trichomes of plants has been well studied in Arabidopsis thaliana. In this paper, Chopra et al.  have identified key regulators of leaf trichome development in Arabis alpina, a species…

“The 1980s were an exciting and revolutionary time for biology, and plant molecular biology in particular,” begins an editorial by Bob Goldberg, Brian Larkins, and Ralph Quatrano, the three Founding Editors of The Plant Cell. They describe why the American Society of Plant Physiologists (ASPP; later,…

The nucleus of plants cells, like other eukaryotes, is full of non-membranous compartments separated by liquid-liquid phases. These complexes are often called nuclear bodies and concentrate proteins and nucleic acids. Disordered protein domains play a critical in their formation. Here, Fang et al. aimed…

This is a great review by Judelson and Ah-Fong on the diverse signals that occur between plants and their oomycete pathogens. The authors start by describing the life- and infectivity-cycles of disease-causing oomycetes, including the familiar plant pathogens, "aggressive" Pythium and "stealthy" Phytophthora.…

Plants possess plasticity for regeneration of organs after damage by physical, biotic or abiotic stress. The mitotically less-active organizer cells, quiescent center (QC) and surrounding initials form the stem cell niche, which is known to play a very important role in activation of the regeneration…

Lateral root development helps plants explore the soil for mineral nutrients and water, and there are environmental and internal cues that precede the formation of lateral root primordia. In Arabidopsis thaliana, some of these internal cues include increased auxin concentrations around lateral root founder…

https://doi.org/10.1105/tpc.18.00663 Mikulski et al. find that the PWO chromatin regulator interacts with a structural component of the nuclear periphery.  By Pawel Mikulski, Cell and Developmental Biology, John Innes Centre, Norwich, UK Background: DNA is wrapped around histone proteins forming…

Zhang et al. discover a deacetylase from rice that highlights the importance regulating acetylation in the cell wall. Plant Cell https://doi.org/10.1105/tpc.18.00894 By Baocai Zhang and Yihua Zhou, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences Background: Plant cells…

Autophagy means “self-eating” in ancient Greek. It’s a process in which cellular components are delivered to lytic vacuoles to be reused. This recycling process promotes abiotic and biotic stress tolerance. In this review, Signorelli et al. highlight in detail plant autophagy in abiotic and biotic…

The fidelity of the chloroplast proteome is a major factor in the functional efficiency of photosynthesis. A RING-type ubiquitin E3 ligase, SP1, is an outer envelope localized protein in the chloroplast which ubiquitinates the protein import translocases (TOC proteins) and thus target them to 26S mediated…

Bai et al. show that an RNA splicing factor promotes normal cell differentiation and stops excessive cell proliferation in the corn kernel. Plant Cell https://doi.org/10.1105/tpc.18.00754   By Fang Baia, Jacob Corllb, and A. Mark Settlesa aHorticultural Sciences Department and Plant Molecular…

Ustilago maydis is a model biotrophic fungus which causes smut disesase in maize, characterized by tumorous symptoms on all aerial parts. Tumor formation in leaves of the host is a result of massive reprogramming by modulation of two processes, hypertrophy (cell expansion) and hyperplasia (cell division).…

To adapt to life on land, plants developed lipid-derived modifications on the surface of aerial organs (shoot). The cuticle forms a multi-layered structure of lipid components at the outermost surface of the organ to protect plant cells from environment stresses. Roots, as the organ specialized for the…

Endomembrane vesicles carry not only secreted proteins but also carbohydrates for cell wall synthesis, yet relatively less is know about this latter process. Wilkop et al. describe a method to investigate the glycan contents of specific subsets of vesicles, to begin to understand how these cargos are…

In the arbuscular mycorrhizal fungal interaction with plants, the fungal partner promotes nutrient acquisition in exchange for some sugar and fatty acids from host plants. This exchange occurs at the symbiotic interface in the plant cortical cells where fungal hyphae form special branched structure called…

Chloroplasts have diverse roles in plant defense, including contributing to the production of defense compounds. Toufexi, Duggan et al. show new data indicating the dynamic relocation of chloroplasts to the contact point of the oomycete pathogen Phytophthora infestans. Infection also causes an increase…

In eukaryotic cells, the movement of cargo between single membrane-bound organelles such as the endoplasmic reticulum (ER), Golgi apparatus, trans-Golgi network (TGN), endosomes, lysosomes, and vacuoles is mediated by membrane trafficking. At the donor organelle, cargo molecules are loaded into transport…

The plant trans-Golgi network (TGN) plays the role of early endosomes and acts as hub for the both secretory and vacuolar trafficking pathways. Two types of TGN, GA-TGN (Golgi-associated TGN) and GI-TGN (Golgi-released independent TGN), have been observed in plants. Here, Uemura et al. explore the cellular…

Progression of the cell cycle central to growth, but during stress conditions plants arrest cell cycle progression to enable the organism to survive. SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1), a plant-specific NAC-type transcription factor, regulates the expression of almost all genes induced by double-strand…

Ganesan et al. investigate protein import into chloroplasts The Plant Cell (2018).  By Iniyan Ganesan and Steven Theg Background: Chloroplasts are the green compartment in plant cells that carry out photosynthesis. Most plant proteins are made in the cytoplasm and many need to cross different…

Huysmans et al. identify cell death regulatory proteins in root cap cells. Plant Cell https://doi.org/10.1105/tpc.18.00293 Background: Some plants, such as giant sequoia trees, can grow into the “Largest Living Things on Earth.” Ironically, most of a tree’s biomass is actually not alive but…

The appropriate spatial arrangement of nuclei is essential for various cellular activities during cell division, growth, migration, and differentiation in eukaryotes. In plants, nuclear positioning is also required for proper responses to environmental stimuli, including pathogen infection, touch, temperature,…

Auxin controls body plan patterning in land plants and it has been proposed to play a similar role in the development of brown algae (Phaeophyta) despite their distant evolutionary relationship with land plants. In flowering plants and many multicellular brown algae, the establishment of the apical-basal…

Plant cells have polarity, with the distribution of the auxin transporter protein PIN2 being a well-described example. Glanc et al. investigated how polarity is re-established following cell division. The authors showed that during cytokinesis, protein trafficking is directed towards the central cell…

Plants devote more than 70% of their available nitrogen to maintaining chloroplast function (Makino and Osmond, 1991). During senescence or under stress conditions, chloroplasts are degraded and their constituent components are recycled. Chloroplasts can be degraded through at least three pathways: (1)…

The establishment of root nodule symbiosis in legume roots involves the perception, infection, and accommodation of nitrogen-fixing rhizobia. The de novo formation of root nodules relies on complex developmental programs coordinated through different tissues via unknown cellular routes. Gaudioso-Pedraza…

Properly functioning guard cells change size in response to myriad stimuli to control the passage of water and gasses through stomata. The change in volume is mirrored by changes in plasma membrane surface area, with membrane moving dynamically between tonoplast and plasma membrane as needed. Bourdais…

In the new Cell Biology issue of Current Opinion in Plant Biology, editors Haswell and Dixit have chosen to focus on quantitative cell biology, arguing that, “if seeing is believing, then measuring is knowing.” Topics of the issue's reviews span parts of the cell (including cell wall, cytoskeleton,…

In Arabidopsis, stomatal guard cells are specified following a set of conserved asymmetric cell divisions (ACDs), starting with a meristemoid mother cell. How do cells establish asymmetric divisions? Several proteins have been identified that are required for this, including BASL and POLAR, transcription…

Small RNAs are known to move between cells and even between organisms. Studies in mammals have shown that extracellular vesicles (EVs) can contribute to small RNA transport, and recently small-RNA containing EVs were identified in plants. Baldrich et al. extend this work with an analysis of the types…

Zhang et al. investigate the assembly of a molecular motor that produces cellular ATP in chloroplasts https://doi.org/10.1105/tpc.18.00075. By Lin Zhang, Lianwei Peng and Jean-David Rochaix Background: The F-type ATP synthase produces nearly all of the cellular ATP, the universal energy currency…

Richardson et al. explore the molecular topology of the chloroplast transit peptide and its nucleotide-dependent movement within the chloroplast protein import channel. Plant Cell https://doi.org/10.1105/tpc.18.00172. By Lynn GL Richardson and Danny J Schnell Background: Chloroplasts, the site…

Plants devote more than 70% of their available nitrogen to maintaining chloroplast function (Makino and Osmond, 1991). During senescence or under stress conditions, chloroplasts are degraded and their constituent components are recycled. Chloroplasts can be degraded through at least three pathways: (1)…

Carboxysomes are protein-bound microcompartments of cyanobacteria that sequester Rubisco and carbonic anhydrase (which converts bicarbonate to carbon dioxide), thus enhancing Rubisco’s carboxylation efficiency. The carboxysome shell is made up of hexamer, pentamer and trimer modules, with selectively…

Franck et al. demonstrate that protein phosphatases ATUNIS1 and 2 negatively regulate cell wall integrity in pollen tubes and root hairs of Arabidopsis. Plant Cell (2018). https://doi.org/10.1105/tpc.18.00284 By C. M. Franck, J. Westermann, S. Bürssner, R. Lentz, D. Lituiev, and A. Boisson-Dernier Background:…

Higashi et al. investigate the function of a heat-inducible lipase in Arabidopsis thaliana. Plant Cell (2018). https://doi.org/10.1105/tpc.18.00347 By Yasuhiro Higashi and Kazuki Saito Background: Land plants suffer from high-temperature stress, exacerbated by climate changes in recent years.…

Liao et al. performed comparative phylogenomic analysis on rice centromeres. Plant Cell (2018). https://doi.org/10.1105/tpc.18.00163 By Yi Liao and Mingsheng Chen Background: Centromeres are necessary for faithful chromosome segregation in eukaryotic organisms. The genomic regions conferring centromere…

Chen et al. investigate the mechanism of MCD1’s action in chloroplast Z-ring positioning in dividing chloroplasts. https://doi.org/10.1105/tpc.18.00189 Background: Chloroplasts are specialized photosynthetic organelles in plants that evolved from an ancient photosynthesizing cyanobacterium through…

Most chloroplast proteins are encoded by the nuclear genome and synthesized on cytosolic ribosomes. N-terminal transit peptides serve as targeting sequences to direct precursors of chloroplast proteins to receptors on the chloroplast surface. These receptors are part of the translocase of the outer envelope,…

Plants exhibit various forms which are determined by the individual cells. The diversity of cell shapes within a single organism is astounding and results from the interactions between the pressure generated by the cell and surrounding tissue as well as heterogeneities in the cell wall composition. As…

Schreier et al. investigate the role of a plastid malate dehydrogenase in early chloroplast development. Plant Cell 30: 1745-1769 Background: Malate dehydrogenases (MDH) are enzymes that are widespread in prokaryotes and eukaryotes. MDH interconverts oxaloacetate and malate, using either NAD or…

The transition from unicellular to multicellular life forms occurred across multiple kingdoms, and in plants is correlated with the expansion of gene families involved in extracellular matrix formation and cell cycle regulation. Green seaweeds acquired their plant-like body independently of other lineages…

Asymmetric cell division is instrumental to development of specialized cells, while symmetric cell division underlies proliferative growth. The defects in cell division plane arise when transition between the G1 to S stage is accelerated, suggesting that the signals leading to division plane position…

Plant cell walls provide mechanical support and define the extent and direction of cell expansion. Regulation of cellulose synthase determines cell wall load bearing and involves the receptor like kinases FEI1/FEI2. To gain further understanding of cell wall integrity regulation Polko et al. performed…

One of the fundamental challenges facing terrestrial plants occurs when CO2 levels are depleted at Rubisco, causing its inefficient oxygenase activity to dominate. Some plants minimize this problem by adding a carbon-fixing step upstream of Rubisco, and various algae and cyanobacteria sequester Rubisco…

Brassinostreroid (BR) regulates the development of the root apical meristem. High levels of BR have inhibitory effects on cell production rates in the meristem and low levels show the opposite effect. Ruan, Halat et al. showed that BR regulates microtubule-associated CLASP (CLIP-Associated Protein) expression…

Recent evidence indicates that H2S acts as an important messenger that affects plant responses to abiotic stresses, including high salinity, drought, heat shock, heavy metals, and oxidative stress. H2S signaling has also been shown to modulate important physiological processes, such as photosynthesis,…

When plant cells are infected by RNA viruses, viral replication complexes are generated in organelle-like structures. These vesicles are important for the replication of viral RNA (vRNA) as well as moving vRNA-protein complexes through plasmodesmata to infect other plant cells. When turnip mosaic virus…

Plasmodesmata are cell-cell junctions that form cytosolic channels between neighboring plant cells. These junctions mediate the exchange of information between cells during various stress and developmental programs by actively regulating the aperture of the channel entrance or ‘pore’. In a new study…

Martinez et al. used a modelling approach to see if it is possible to predict the location of a cell’s future division plane. In most cases the cell divides according to strict geometric rules, such that the newly formed wall will have a minimum area (described as a soap-film minimization model). However,…

Ploidy refers to the number of genomes contained within a nucleus. Ploidy levels can increase through whole-genome duplication, which affects every cell equally, and through endoreduplication, a cell-by-cell process in which DNA synthesis is not accompanied by cytokinesis. Robinson et al. investigated…

The Casparian strip in the endodermis acts a barrier to allow the selective absorption of water and nutrients. Because of its cell-specific presence, the Casparian strip is considered a marker for functional endodermis. The cellular identity of endodermis is controlled by two transcription factors, SHR…

Subcellular trafficking helps determine the development of the plant through for instance the regulation of polar localization of auxin transporter PIN-FORMED (PIN) proteins. PIN trafficking or recycling is maintained by GNOM, a BFA-sensitive ARF GEF (ADP-ribosylation factor guanine nucleotide exchange…

ARF GEFs (ADP-ribosylation factor guanine nucleotide exchange factors) play a major role in the intracellular trafficking and eventually regulate developmental cues. As plants contain multiple ARF GEF with very similar sequences, chemical genetics approaches are more appropriate to uncover their function…

Finding genes that function in plant development often requires mutant screening, but probing the wealth of natural variation can provide important insights as well. A major focus of developmental biology is uncovering the mechanism behind cell polarity, that is, how components are deposited asymmetrically…

Every plant organ, from tuber to tepal, is formed by cells that divide along precisely placed cell plates. While much is known about the molecular biology behind cell plate formation (e.g., Gu et al., 2016), why cells divide where they do is much less clear. Dividing cells have much in common with soap…

The plant vacuole makes up to 90% of the cell volume and its dynamics are important for regulating growth, development and stomatal movement. Membrane fusion between the vacuole and the smaller vesicles is at the heart of central vacuole establishment. Homotypic fusion and vacuole protein sorting…

Most of the proteins that function inside of mitochondria or chloroplasts are encoded in the nucleus, translated in the cytosol, and imported through one or two membrane-localized translocons. (In mitochondria the outer- and inner-membrane translocons are called TOM and TIM, and in chloroplasts they…

Zizhen et al. perform electron tomography and correlative gene expression analyses of thylakoid assembly in greening Arabidopsis cotyledons Plant Cell (2018) https://doi.org/10.1105/tpc.17.00972 By Byung-Ho Kang Background: The chloroplast produces carbohydrates and molecular oxygen from water,…

Mateo-Bonmatí et al. have found novel components of the Arabidopsis epigenetic machinery. Plant Cell (2018). https://doi.org/10.1105/tpc.18.00300  By Eduardo Mateo-Bonmatí, Lucía Juan-Vicente, Riad Nadi, and José Luis Micol Background: In multicellular organisms, most cells contain the same…

Chen et al. reveal a multilayer molecular protection system functioning in Arabidopsis and human cells https://doi.org/10.1105/tpc.18.00236 By Mingjia Chen and Claus-Peter Witte Background: RNA possesses over 100 distinct posttranscriptional modifications in eukaryotic species. N6-methyladenosine…

Complex developmental programs regulate tissue and organ formation throughout the green plant lineage, from early diverging non-vascular lineages (bryophytes) to vascular flowering (angiosperm) plants. In the model liverwort Marchantia polymorpha, epidermal patterning gives rise to surface structures…

Corem et al. demonstrate a switch in DNA methylation patterns across the tomato genome. The Plant Cell (2018). https://doi.org/10.1105/tpc.18.00167. By Shira Corem, Tzahi Arazi and Nicolas Bouché Background: Crop genomes are covered by transposons, which are DNA sequences that can jump from one…

Once viewed merely as inert packets of metabolic energy that are mobilized during postgerminative growth, lipid droplets (LDs) have emerged as dynamic organelles with important roles in processes ranging from stress responses to hormone signaling (Pyc et al., 2017). LDs consist of a core of neutral lipids…

Most proteins within a cell are encoded in the nucleus and then translated in the cytosol, but how do they end up where they need to be? With the exception of the few proteins expressed within the chloroplast, the process of shipping nucleus-encoded proteins into the chloroplast is dependent on N-terminal…

Yamada and Goshisma identify a nuclear transporter that controls the position of the nucleus during cell growth in plants https://doi.org/10.1105/tpc.18.00038. Background: Transportation of cellular components to appropriate locations for their activity is a critical aspect of cell function. Microtubule…

Yao et al. found that OsPM1 can move the plant hormone abscisic acid into rice cells. https://doi.org/10.1105/tpc.17.00770. By Lingya Yao and Xiaochun Ge Background: Abscisic acid (ABA) is an important plant hormone that regulates plant seed dormancy and stress responses, especially drought responses.…

Background: Maize is one of the world’s leading crops that is used for food, feed, and fuel. Maize is vulnerable to adverse environmental conditions that lead to production losses. Such conditions can upset delicate cellular processes in maize cells such as protein folding in the endoplasmic reticulum…

Roberts et al. investigate cell wall synthesis in Physcomitrella patens. The Plant Cell (2018). https://doi.org/10.1105/tpc.18.00082. By Alison Roberts and Eric Roberts Background: The health-promoting soluble fiber in whole grains is rich in mixed-linkage glucan (MLG), so called because it consists…

Breker et al. provide a large collection of mutants in cell-cycle-essential pathways in the green alga Chlamydomonas reinhardtii https://doi.org/10.1105/tpc.18.00071. By Michal Breker Background: The cell division cycle is a set of tightly regulated and orchestrated events that lead to accurate…

Source: SeedQuest Some plants like the giant sequoia trees can grow into the “Largest Living Things on Earth”. Ironically, most of a tree’s biomass is actually not alive, but is formed by persistent cell corpses that are collectively called wood. Wood development is terminated by a tightly controlled…

Global climate change is one of the most pressing issues facing our world today. The impact of increasing temperatures can be felt in diverse areas, including human health and disease, natural ecosystems, and food security. In the agricultural sector, deciphering how plants respond to changing environmental…

Cells use a sophisticated sorting system to ensure that proteins get to the proper destination. Proteins that are supposed to stay in the ER carry special tags (KDEL or HDEL, recognized by the ERD2 receptor) that prevent them from being swept along with other proteins out of the ER and into the Golgi.…

Plant photosynthesis occurs in the chloroplast, the green organelles that are the most famous members of the plastid family. Chloroplast biogenesis starts with illumination at germination, when the colorles, non-photosynthetic proplastid acquires photosynthetic activity as it greens. Gaining photosynthetic…

Chen et.al. demonstrate that phosphatidic acid mitigates S-RNase signaling in pollen by stabilizing the actin cytoskeleton. Plant Cell (2018). https://doi.org/10.1105/tpc.18.00021 By Jianqing Chen, Peng Wang, Shaoling Zhang, and Juyou Wu Background: The success of sexual reproduction in flowering…

Stromules (or stroma-filled tubules) have been observed for more than 100 years, but uncertainty remains about their formation and function. Stromules are extensions of the plastid membrane that form highly dynamic tubule-like structures that sometimes interact with other plastids or organelles. Hypothetical…

Wang et al. show that abscisic acid-inducible genes encode lipid degrading enzymes that release polyunsaturated fatty acids from chloroplast lipids as precursors for jasmonic acid production leading to biotic defenses in Arabidopsis. Plant Cell doi.org/10.1105/tpc.18.00250 By Kun Wang and Igor Houwat Background:…

Zauner et al. investigate the mechanism of protein re-purposing. The Plant Cell (2018). https://doi.org/10.1105/tpc.17.00963. By Florian B. Zauner, Elfriede Dall and Hans Brandstetter Background: Plants cannot run away from herbivores, drought, or heat. To withstand adverse conditions, plants have…

Arabidopsis plants have epidermal pavement cells (the cells that make up the bulk of the epidermis, other than guard cells or trichomes) that are often described as “jigsaw puzzle” shaped, and, because Arabidopsis is such a useful model organism, we have nice models for how these distinctive shapes…

Guard cells are undoubtedly fascinating and frequently reviewed in terms of both their developmental programming and the intracellular signals that contribute to their function. This review, by Woolfenden, Baillie et al., covers a less familiar topic, that of the biophysical constraints to the mechanics…

The pathogenic oomycete Phytophthora capsici secretes RXLR effector proteins into plant cells to subvert host cell machinery and facilitate disease. Several RXLR effector proteins have been characterized to date, however, Phytophthora species encode a vast array of effector molecules that likely target…

The microtubule (MT) cytoskeleton is a dynamic network of self-assembling highways that, together with the help of motor proteins, promotes intracellular transport and the formation of magnificent structures such as the preprophase band, mitotic spindle, and phragmoplast (Nebenführ and Dixit, 2018). …

During seedling greening, chloroplasts are formed from proplastids. Liang and Zhu et al. used a combination of 3D electron tomography of cryo-fixed Arabidopsis cotyledons at various times after illumination to track their development. The fine structure images, accompanied by transcriptomic analysis…

When plants are exposed to excessive light, photoinhibition occurs and chloroplasts become damaged. Photodamaged chloroplasts undergo vacuolar digestion through a poorly understood autophagic process called chlorophagy.  In general, cell biologists recognize two types of autophagy: macroautophagy and…

Within cells there are vast numbers of different activities and processes occurring simultaneously. In eukaryotic cells, some of these processes are segregated into distinct membrane-bound compartments. Cuevas-Velazquez and Dinneny review how membraneless compartments also contribute to subcellular organization,…

The three-dimensional arrangement of DNA within the nucleus clearly affects gene expression, but its contribution remains relatively unexplored as compared to other factors. Sotelo-Silveira et al. review new chromosome conformation capture (3C) and derived techniques for assessing genomes in 3D, as well…

A key question in plant stress physiology is how the plant perceives stress in order to mitigate its effects. Heat (and other) stress can lead to an accumulation of unfolded or misfolded proteins in the endoplasmic reticulum, which initiates the Unfolded Protein Response (UPR), leading to a change in…

Iowa State University AMES, Iowa – Plant scientists at Iowa State University have completed a new study that describes the genetic pathways at work when corn plants respond to stress brought on by heat, a step that could lead to crops better capable of withstanding stress. The findings, published…

Üstün  et al. show that pathogenic Pseudomonas enhances the autophagic turnover of proteins in Arabidopsis https://doi.org/10.1105/tpc.17.00815. By Suayib Üstün and Daniel Hofius Background: Autophagy and the proteasome are the major pathways for protein degradation in eukaryotes. While the…

Adamowski et al. use CRISPR to investigate the function of plant auxilin proteins https://doi.org/10.1105/tpc.17.00785. By Maciek Adamowski Background: Endocytosis is one of the basic pathways of cellular trafficking. By endocytosis, proteins located in the plasma membranes, for instance receptors,…

By Rumen Ivanov and David G. Robinson Our knowledge of vacuole biogenesis and the transport of proteins to the vacuole has advanced consistently over the last 30 years. In meristematic cells, the tonoplast appears to develop directly out of the endoplasmic reticulum (Viotti et al., 2013). Once it is…

Pollen tubes are remarkable vehicles that deliver immobile sperm nuclei from the stigma to the ovule during angiosperm reproduction. Their journey delicately balances turgor pressure with the precise spatiotemporal regulation of polarized growth machinery to navigate pollen tubes and their cargo to the…

Cell division is essential for growth and reproduction. The cell cycle machinery is well conserved between yeast and animals, but whether this conservation extends to the plant lineage is not clear, having diverged over two billion years ago: ample time and opportunity for divergence in sequence and…

When you try to tip rocks out of a bucket, nothing happens until the steepness of the angle is sufficient to start them shifting (the “avalanche angle”). By contrast, water starts moving with even the slightest tilt to the bucket. Now think about the gravity sensing particles in plant cells, starch-rich…

Small RNAs (sRNAs) trafficking between host plant and pathogens can occur in a wide range on interactions. Pathogen-produced sRNAs have been shown to suppress host plant immunity, and conversely host plant-derived sRNAs can reduce pathogen virulence by targeting pathogenic genes of the pest. Nevertheless,…

The corn smut fungus Ustilago maydis manipulates maize tissues and cells through the secretion of effectors that modulate host protein activities. In a recent article published in Nature Communications, Ma et al. characterize a highly repetitive effector protein family (Rsp3, repetitive secreted protein…

Zhang et al. show how PSK initiates Ca2+- and auxin-dependent immunity https://doi.org/10.1105/tpc.17.00537.  By Huan Zhang, Zhangjian Hu and Kai Shi Background: During plant-microbe interactions, some small secreted peptides are secreted into the apoplast between plant cells as damage-associated…

Majeran et al. investigate how plant cells target proteins to membrane compartments https://doi.org/10.1105/tpc.17.00523 By Wojciech Majeran, Thierry Meinnel & Carmela Giglione Background: Living cells are encased in an oily barrier, the plasma membrane, made up of a double layer of lipids…

By Karina van der Linde and Virginia Walbot  Background: In contrast to animals in which meiotically competent cells develop in embryos, plants switch from vegetative to reproductive growth only during flowering. In maize, the most productive cereal crop, the tassel contains male flowers in which…

Autophagy has been defined as non-specific self-eating to obtain material that will be used for key processes within the cell. Even through authophagy has been demonstrated to be very important, its role during plant-bacteria interactions is not well known.  Üstün et al. examined interactions between…

RAB proteins are membrane-anchored proteins that coordinate and regulate vesicle trafficking. Plants contain two group of RAB5 proteins, canonical (ARA7, RHA1) and plant-specific (ARA6), which share a common activator, VPS9A (Vacuolar Protein Sorting 9A). Ito et al. used an activated (GTP-bound) version…

In its simplest definition, a plastid is an organelle that manufactures and stores essential chemical compounds used by its host cell. Numerous plastids exist beyond the familiar chloroplast. Chromoplasts synthesise and store carotenoid pigments, and provide their hosts with district yellow, orange or…

Magnaporthe oryzae is a devastating fungal pathogen that routinely threatens rice crop yields. Rice blast infection occurs when fungal hyphae penetrate into and proliferate within living plant cells, moving intracellulary from cell-to-cell through plasmodesmatal junctions. In a recent article published…

Potassium (K+) and calcium (Ca2+) ions are important for stomatal function in seed plants,  however little is known about the contributions of these ions in the stomata of bryophytes and early-branching vascular plants. Voss et al. focus on how fern stomata regulate ion transport. Injection of K+ into…

Meiotic drive is essentially a subversion of meiosis such that particular regions or alleles are preferentially favored for transmission to the progeny. Abnormal chromosome 10 (Ab10) is a classic example of meiotic drive in maize that converts heterochromatic chromosomal knobs into motile ‘neocentromeres’.…

An image from a paper published in Plant Cell is featured as The Scientists "Image of the Day" Image of the Day: Pseudomonas Autophagy Researchers identify antibacterial functions of cell death in Arabidopsis when the plant is infected with Pseudomonas. By The Scientist Staff | March 30, 2018 A…

During seed development, protein reserves and minerals are stored in specialized vacuoles called protein storage vacuoles (PSVs). PSVs are functionally different from the lytic vacuoles (LVs) that serve a lysosome-like role in vegetative plant tissues. Embryonic vacuole (EVs) are also present during…

Plasmodesmata are contiguous cell-cell junctions that provide an avenue for intracellular (symplastic) communication between neighboring plant cells. In recent years, researchers have unravelled key aspects of plasmodesmata development and function in cell-cell signalling during a multitude of responses…

By Daniel Cosgrove The primary wall of a growing cell is a versatile, subtle, and dynamic structure, with unique properties and functions in the life of the plant (Burton et al., 2010). When a cell grows, its wall stretches irreversibly as the cell enlarges in volume. Cells can start and stop this…

Adaptor proteins (AP) are involved in sorting proteins and are able to recognize cargo and coat proteins during vesicle formation. AP-3 specifically targets protein cargoes to vacuoles. Feng et al. investigate the role of AP-3 in plant reproduction. ap-3 mutants have reduced seed set that is characterized…

Passage cells are a subset of interspersed root endodermal cells that are unsuberized, which is thought to aid in transport because suberin inhibits transcellular transport. In Arabidopsis, suberization follows a stereotypic pattern which responds to many stress conditions, partly mediated by abscisic…

A functioning cell depends upon the appropriate production of proteins and macromolecules. The other end of the process, degradation and removal, is just as critical and just as selective. Marshall and Vierstra review autophagy (“self-eating”) in plants, connecting early work in yeast to genetic,…

Ercoli et al. investigate how GIF genes control root development https://doi.org/10.1105/tpc.17.00856 By María Florencia Ercoli and Javier Palatnik Background: Plants, unlike animals, have the ability to generate new organs throughout their life cycle. This capacity relies on meristems, which…

Zhang et al. show that GIF1 regulates the determinacy of meristems and controls tassel architecture in maize. The Plant Cell (2018). https://doi.org/10.1105/tpc.17.00791 Background: Plant architecture results from a balance of indeterminate and determinate cell fates. Cells with indeterminate fates…

Kurzbauer et al. discover a role for the Fanconi anemia D2 plant homogue in promoting meiotic crossover formation. https://doi.org/10.1105/tpc.17.00745 by Marie-Therese Kurzbauer and Peter Schlögelhofer Background: Meiosis is a specialized cell division and generates the basis for genetic diversity…

Three letters to Plant Physiology address the role of vesicles in auxin transport, discussing the evidence and conclusions from a recently published paper from three perspectives. Does auxin accumulate in endocytic vesicles? If so, how, and why? The Letters address both the methods used and the intrepetation…

Trafficking within a cell can occur through clathrin-mediated endocytosis (CME). CME depends upon coating plasma membrane vesicles with clathrin and adaptor proteins but the mechanism is unclear in plants. Adamowski et al. establish a means with which to study this process in order to further elucidate…

BRI1 (BRASSINOSTEROID INSENSITIVE1) is a plasma-membrane localized brassinosteroid (BR) receptor that is endocytosed to internal membranes following BR binding. In this study, Zhou, Liu et al. provide a mechanistic model of BRI1 endocytosis through ubiquitination. They identified two E3 ubiquitin ligases,…

Root hair outgrowth requires the plant hormone auxin and polarized tip growth and cell wall deposition. Schoenaers et al. showed that the plasma membrane-localized receptor-like kinase ERULUS (ERU) regulates tip growth in root hairs. ERU is regulated by auxin via ARF7 and ARF19 transcription factors,…

Plant growth and development consist of highly organized cellular patterns and depend on the directional growth and orientation of cells. Understanding microtubule dynamics is key to deciphering the formation of cellular shape and growth direction. In this research, Chakrabortty  et al. employed analytical…

In proliferating tissues, plant cells start small and then expand to up to 100 times their original size. Sapala, Runions and collaborators studied the relationship between mechanical stress and shape to see if mechanical stress could affect the shape of epidermal cells. Simulations were run to see the…

Gibberellins including gibberellic acid (GA) are plant hormones required for growth and development. GA has been reported to regulate tropic responses by modulating plasma membrane localization of PIN auxin transporters. In this study, Salanenka et al. focused on the mechanism of GA-mediated protein…

In plant cells, vacuoles store and degrade wastes including proteins. Vacuolar targeting and fusion by endosomes are specified by SNARE complexes at the membrane. In this study, Takemoto et al. studied the function of two tethering complexes, HOPS (Homotypic fusion and Protein Sorting) and CORVET (Class…

Plasma membrane lipids including phosphatidylinositol phosphates (PIPs) are often depicted as forming a featureless plane that serves mainly as a barrier, but in reality they show considerable spatial diversity. PIPs contribute to anchoring and positioning proteins and protein networks, so there is much…

It has been shown previously that cortical microtubule reorganization contributes to adaptation to salt stress; however, the upstream factors that signal this response are not know. Ethylene has been shown to regulate microtubule stability and organization in roots and etiolated hypocotyls. Ethylene…

The fungal pathogen Magnaporthe oryzae causes one of the most destructive diseases of rice, destroying around 10-30% of rice production world-wide. The pathogen undergoes different developmental changes and produce specialized infectious structures in order to rapidly proliferate within the host cells.…

Plant cell walls have recently been revealed as an essential factor of plant environment monitoring system, much more than just a passive defensive barrier as previously thought. In a recent work, Bacete et al. have reviewed how changes to plant cell wall integrity affect disease resistance. More specifically,…

Ethylene is an important mediator during plant adaptation to salt stress. During salt stress, ethylene has been shown to promote microtubule (MT) stability and organization. Dou et al. further examine this pathway using Ag+ to block ethylene signaling in addition to using various mutants. In wildtype…

Maekawa et al. find a ribosome production monitoring system in Arabidopsis thaliana Plant Cell (2017) https://doi.org/10.1105/tpc.17.00778 By Shugo Maekawa, Tetsuya Ishida, Shuichi Yanagisawa Background: Protein is produced by ribosomes consisting of a number of proteins and several RNAs (ribosomal…

Yang et al. reveal a conserved H3K4me3 recognition mechanism shared by both plant and animal KDM5 histone demethylases. The Plant Cell (2017). https://doi.org/10.1105/tpc.17.00666 By Z. Yang, Q. Qiu, X. Cao and J. Du Background: Histone methylation is a conserved gene regulation mechanism in plants…

Hohenstatt et al. describe a new recruiter of PcG chromatin regulators affecting flowering and meristem identity in Arabidopsis. https://doi.org/10.1105/tpc.17.00117 By Pawel Mikulski 1) BACKGROUND: Polycomb group (PcG) proteins are key regulatory proteins involved in maintaining the ability (and…

Communication between chloroplast and the nucleus is crucial to accomodate changes in the environment as well as regulate development of the chloroplast itself. Five GENOMES UNCOUPLED (GUN2 to -6) genes were previously described to regulate plastid-to-nucleus communication by affecting the synthesis…

Cyclins and cyclin-dependent protein kinases (CDKs) are critical regulators of cell cycle progression. Although CDK1 is essential for mitosis in animals and fungi, CDKA, the plant and algal ortholog of CDK1, is not essential for cell division in Arabidopsis (Nowack et al., 2012). By contrast, CDKB is…

The nucleus is a dynamic organelle whose positioning and movement is highly coordinated throughout plant development and differs between cell types. Upon the initiation and subsequent elongation of root hairs, the nucleus moves from a central position to the tip of the growing root hair. Nakamura et…

Cytokinin is a phytohormone involved in many plant processes such as cell proliferation, apical dominance, leaf senescence, tissue patterning, organ initiation, environmental responses…  To allow for effective control of all these processes, cytokinin concentrations need to be continuously adjusted.…

By Catalin Voiniciuc, Markus Pauly, and Björn Usadel All plant cells are surrounded by complex walls that play a role in growth and differentiation of tissues. Walls provide mechanical integrity and structure to each cell, and represent an interface with neighboring cells and the environment (Somerville…

Godfroy et al investigate basal cell fate determination in the brown alga Ectocarpus https://doi.org/10.1105/tpc.17.00440 BACKGROUND: Brown algae are multicellular photosynthetic marine organisms living on rocky shores across the globe and representing one of the most developmentally complex groups…

Robinson et al. develop a method to measure mechanical properties of plant tissue with cellular resolution https://doi.org/10.1105/tpc.17.00753 Background: Plant growth is controlled by the extensibility of the cell wall and the turgor pressure inside. The spatial regulation of these properties…

Plant Physiology has released a focus issue on the topic of Cellular Dynamics, which includes Updates on topics ranging from Actin Dynamics to Wall Growth. The Editorial by Szymanski, Bassham, Munnik, and Sakamoto provides an excellent overview of the current state our understanding of plant cell dynamics.…

Bisphenol A (BPA) is known for its negative impact on mammalian cell lines and, recently, as an emerging environmental pollutant. BPA, readily taken up and metabolized by plants, results in many growth and developmental defects, from disrupted mitotic microtubule (MT) arrays to altered calcium fluctuations…

The plant cytoskeleton determines cell shape and integrity by delivering cellulose microfibrils and other cell wall components to the plasma membrane and cell wall. Auxin is involved in establishing the polarity of cell expansion and auxin distribution is partly regulated by actin. Sahi et al. examine…

All phytopathogens encode for a toolbox of secreted proteins called ‘effectors’ that promote disease formation in the best possible way. Effectors are either acting in the apoplastic space or are translocated to the host cell to target diverse processes and modulate the host using enzymatic activities.…

Successful fertilization in plants requires sperm cells (SCs) to be carried along the growing pollen tube (PT) until reaching the female gametophyte where the PT then bursts to release the SCs. One challenge PTs must overcome in order to achieve fertilization is deciding to rupture or not to rupture.…

Schmitz et al. investigate the physiological significance of the glyoxylase system  in Arabidopsis https://doi.org/10.1105/tpc.17.00258 By Jessica Schmitz and Veronica G. Maurino BACKGROUND: In every living cell, side reactions of enzymes and spontaneous reactions of metabolites inevitably…

Plants can reach impressive heights, thanks to the mechanical stability provided by the cell walls. The required strength is ensured by coordination of cell wall deposition and cell expansion. Plant-specific calpain (DEK1) regulates axial stem growth, as lines overexpressing the calpain domain develop…

By Amir Bidhendi and Anja Geitmann Abstract Plant cells come in a striking variety of different shapes. Shape formation in plant cells is controlled through modulation of the cell wall polymers and propelled by the turgor pressure. Understanding the shaping aspects of plant cells requires knowledge…

Understanding the metabolic pathways underlying oil production and the precise intracellular localization of lipid droplets is crucial for successfully engineering microalgae for biofuel production. The microalga Chlamydomonas reinhardtii accumulates considerable amounts of starch and triacylglycerol…

The plant cytoskeleton forms a dynamic and complex architecture in all plant cells and comes with a myriad number of functions, from allowing intracellular transport to regulating gene expression. In this review, Yoshihisa Oda focuses on the purposes of cortical microtubule (cMT) arrays, which are anchored…

Plant growth is determined not only by cell division, but also by loosening of the cell wall. Arsuffi and Braybrook review our understanding of the mechanisms of cell wall loosening. Already in the 1970s scientists started to observe that low pH leads to increased growth, using destructive experiments.…

By Daniel B. Szymanski and Christopher J. Staiger A dynamic network of filamentous elements, the cytoskeleton, holds the key to patterning of the cell wall during growth. This review focuses on the actin cytoskeleton during cell morphogenesis. The field is progressing rapidly, enabled by forward-…

By Michel Ruiz Rosquete, Destiny Jade Davis, and Georgia Drakakaki Abstract Transport networks may be defined as sets of connected nodes or hubs where cargo from different origins are sorted to their final destinations. The trans-Golgi Network (TGN) is the most discussed and arguably busiest hub…

Plasmodesmata are plasma membrane-enclosed pores between cells that were initially described by Tangl in 1879 as ‘open communications’ between protoplasts of endosperm cells. These structures are regulated by callose deposition from the apoplast and play an important regulatory role in stress and…

Pollen tubes exhibit unidirectional, polar growth because vesicles carrying compounds required for growth  are selectively transported to the growing apex. The phosphoinositide PtdIns(4,5)P2 accumulates at the apex and  is thought to help with vesicle targeting. Helpel et al. showed that the lipid…

KATANIN is a AAA ATPase protein which, according to the most recent models, is able to track along microtubules (MTs) and sever emergent γ-TUBULIN and AUGMIN-nucleated MTs. This severing event occurs at MT cross-over areas, particularly where there are MT lattice defects, promoting disassembly of unfavorable…

Plants repair wound sites through the formation of unorganized cell masses called calli, which can also serve as progenitors of new organs. Callus formation and organ regeneration often entail cell cycle re-entry of quiescent cells, which is achieved through the re-activation of core cell cycle regulators…

Plant glandular trichomes can store and secrete great amounts of volatile organic compounds (VOCs) that are important for a variety of processes, from development to interacting with herbivores. VOCs accumulate in specific extracellular spaces which can be subcuticular or intercellular. The active transport…

In order for a cell to expand, its volume needs to increase and the cell wall needs to loosen up. There are multiple processes resulting in cell wall loosening, but not all of them result in extension. Cosgrove differentiates different structural, mechanical and physiocochemical processes that lead to…

Pollen cells have a fascinating ability to transform from a small spherical cell to a very elongated shape known as the pollen tube (PT) during fertilization. Pollen cells must navigate through the female tissue, find an ovary, and burst to release the two sperm cell nuclei as well as the vegetative…

Both plants and animals have a sophisticated immune system comprising receptors to detect pathogen-encoded epitopes or virulence molecules. These receptors are programmed to recognize pathogen ligands which are rapidly evolving over an evolutionary time. However, the structural basis of ligand perception…

By Gil Feiguelman, Ying Fu, and Shaul Yalovsky Introduction Rho of Plants (ROP) proteins also known as RACs are the plant specific subfamily of Rho small GTP binding proteins, referred to here as small G proteins (Zheng and Yang, 2000; Brembu et al., 2006; Elias and Klimes, 2012). Like other members…

The cuticle is a cell-wall polymer that protects against desiccation, pathogens and UV light.  Domínguez et al. provide an open-access editorial that describes this fine collection of articles covering all aspects of the plant cuticle, from its evolutionary origins to its ecological significance. Within…

During embryogenesis, plastids arrest their differentiation as etioplasts (characterized by the distinctive prolamellar bodies, PLBs), and remain poised  to complete their differentiation into functioning chloroplasts upon exposure to light. Liu et al. explored the factors that interact to effect this…

SHORT-ROOT (SRT) is a transcription factor that has previously been shown to move between cells and so contribute to developmental patterning. Spiegelman et al. investigated the cellular machinery that contributes to SRT’s movement. Previous work showed that the movement of SRT depends on the endosome…

Autophagy is a major pathway involved in degradation and recycling of the cytoplasmic components in a cell. This pathway is functionally well conserved in maintaining cellular homeostasis and modulation of stress responses among yeast, plants and animals. Recent evidence suggests that autophagy targets…

The jigsaw-puzzle shape of the epidermis layer has been puzzling the scientists for some time now. Majda et al. examine the shape of the epidermis cells from the cell wall perspective. Mutations leading to even minor changes in cell wall composition significantly affected pavement cell geometry.…

While much is known about the processes involved in stomatal movement and the processes involved in the transpiration of leaves, there has been no framework to bridge this micro-macro divide. Wang and colleagues bridge this divide through OnGuard2, a quantitative systems platform that uses the molecular…

By Takaki Yamauchi, Timothy D Colmer, Ole Pedersen, Mikio Nakazono Introduction Root acquisition of water and nutrients is essential for plant growth and crop productivity (Lynch, 2015). An improved understanding of root system development and functioning, to identify root traits contributing to…

By Gregory D. Reynolds, Chao Wang, Jianwei Pan, Sebastian Bednarek Introduction The plasma membrane (PM) serves as the interface between the cell and its environment. Accordingly, cells have the capacity to modulate their complement of PM-associated receptors, transporters, channels, lipids, and…

Much of our knowledge concerning ABA-induced stomatal closure comes from genetic models such as Arabidopsis and Vicia faba. Watkins et al. explore the mechanism of ROS production in this abiotic stress pathway in an important agricultural crop: tomatoes (Solanum lycopersicum). Specifically, they are…

The capacity of plants to regenerate new shoots from differentiated tissue – a process called de novo shoot regeneration – confers plasticity to plant development and has also important agricultural applications. Previous studies revealed that DNA METHYLTRANSFERASE1 (MET1) inhibits shoot regeneration…

Despite vast differences across all living organisms, most eukaryotes display some form of cellular polarity which enables them to carry out specialized functions. The coordination of cell polarity within a single tissue layer is known as planar polarity. Nakamura and Grebe highlight the unique execution…

Plant cell wall architecture is a very complex specific design and the interaction between xylan and cellulose is believed to be that way too. Grantham et al. reveal the details of the association between xylan and cellulose using mass spectrometry and NMR in Arabidopsis. ESKIMO1 (ESK1) is a xylan-specific…

By Junmarie Soto-Burgos, Xiao-Hong Zhuang, Liwen Jiang, and Diane C. Bassham Autophagy, literally defined as “self-eating”, functions as a degradation process by recycling cytoplasmic contents under stress conditions or during development. Upon activation of autophagy, a membrane structure known…

Eisenach et al. discover A new ion channel of the plant vacuole helps plants react to drought https://doi.org/10.1105/tpc.17.00452 By Cornelia Eisenach Background: Stomata are small pores on plant surfaces that facilitate diffusion of CO2, O2 and water vapor between plant and atmosphere.  During…

Schneider et al. explore how secondary cell walls are made. The Plant Cell 2017.  https://doi.org/10.1105/tpc.17.00309 Background: Plant cells are surrounded by robust cell walls that function as dynamic extracellular skeletons and protect plants against their environment. The cell walls make up…

Zhang et al. explore the behavior of chromosomes during meiosis. The Plant Cell (2017). https://doi.org/10.1105/tpc.17.00287 By Fanfan Zhang Background: In meiosis, plants, animals, and fungi reduce their chromosome numbers by half to form gametes (sperm and eggs) that can fuse to form a cell…

Walker et al. explore how the environment shapes root architecture. The Plant Cell 2017.  https://doi.org/10.1105/tpc.16.00961 By Liam Walker Background: To acquire nutrients and anchor themselves, plant roots spread both vertically and horizontally in soil. Plants typically have a primary root…

Peroxisomes are endoplasmic reticulum-derived membrane-enclosed organelles in which many oxidative enzymatic reactions are compartmentalized. These reactions and their products contribute to energy production, detoxification, and signaling. Kao et al. review our understanding of the plant peroxisome,…

Plasmodesmata (PD) are complex, regulated channels between plant cells that facilitate the movement of signals, metabolites and pathogens, but their small size makes them difficult to study. Previously, Kraner et al. identified an Arabidopsis mutant that produced fewer, simpler plasmodesmata. In their…

Pectin is a polymer that holds cell walls together and stiffens the walls, but what happens when those cell walls need to move, for example when cells (including guard cells) expand? Rui et al. started with a guard-cell specific transcriptome to identify genes encoding cell-wall modifying enzymes. They…

Plant growth and development are extremely adaptable to changes in the external environment, including nutrient status, light quality and intensity, and temperature. Thanks to their developmental plasticity, plants can also initiate new organs from differentiated tissue following wounding, to the benefit…

Aphids are highly destructive insect pests—in addition to robbing plants of sugar-rich phloem sap, they carry viruses that can be deadly to the plant. To reach the phloem sap, aphids must penetrate the plasma membrane of sieve elements. Mature sieve elements, which are virtually empty, translocate…

A hallmark of xylem development is the deposition of secondary cell wall material in specific patterns (reviewed in Patrick et al, 2007). These cell wall deposits structurally reinforce the xylem to withstand negative pressure during water transport and differ in different xylem cell types. While it…

Convincing molecular and biochemical evidence exists that members of the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX PROTEIN (TIR1/AFB) receptor family are auxin receptors that trigger auxin-induced gene expression and hypocotyl growth through enhanced expression of SMALL AUXIN UP RNA genes.…

Vesicle traffic to and from the plasma membrane plays an integral role in regulating protein localization and activity, membrane composition, and cell surface area. Clathrin is a structural protein that forms a lattice-like complex composed of two H chain subunits (CHC1 and CHC2) and two light chain…

Some plants are able to suppress inbreeding through a system called self-incompatibility, in which “self”-pollen is unable to reach “self” eggs. Self-incompatibility has evolved multiple times and takes several forms. Goring reviews the cellular processes of self-incompatibility that occur in…

Plasmodesmata are tiny channels between cells that allow intercellular movement of messages and metabolites as well as pathogens. They are structurally complex and usually have a central strand of endoplasmic-reticulum (the desmotubule) that passes between adjacent cells, connected by spoke-like elements…

Cell division in plants is a structurally beautiful process that involves striking and dynamic changes in the cytoskeleton, endomembranes, and nucleus. However, as authors Smertenko et al. observe, “Current plant cytokinesis terminology was developed using data generated by fluorescence microscopy…

Photosynthesis in aquatic organisms is made difficult due to the low solubility of CO2 in water. Algae such as Chlamydomonas rheinhardtii overcome this limitation through a carbon-concentrating organelle called a pyrenoid. Two papers in Cell redefine our understanding of the pyrenoid structure. Mackinder…

Aphids are major pests that damage plants by sucking out phloem sap and as by acting as vectors in transmission of more than 300 different viruses. Kloth et al. used a high-throughput method involving video-tracking of aphid behavior on leaf discs to score 350 Arabidopsis accessions for aphid resistance.…

Pathogenic microbes interfere with the host cellular and physiological processes to promote infection. This interaction is monitored by pathogen molecules called effectors that either act in intercellular space or enter the host cells. Mechanisms underlying the uptake of these effectors are not fully…

Pathogenic microbes manipulate host plants by secreting effector molecules that interfere with immunity. Bacterial phytopathogens achieve this using specialized secretion apparatuses that act as molecular ‘hypodermic needles’ to inject effector proteins directly into plant cells. In comparison, effector…

Changes in guard cell turgor pressure result in stomatal opening and closing, balancing CO2 uptake with transpiration. These dynamics have been studied as early as the 1800s and much knowledge has been gained regarding the components involved in this process, yet we are still far from a unified model…

Wear et al. examine replication programs in plants. The Plant Cell 2017. https://doi.org/10.1105/tpc.17.00037 By William Thompson, Emily Wear, and Linda Hanley-Bowdoin DNA replication is fundamental to all life, as it is the process by which genetic material is duplicated so it can be passed from…

Ion channels are proteins that regulate the passage of ions across membranes. Ion channels are regulated in diverse ways – some are calcium-regulated, some are pH sensitive, some are charge sensitive, and some are sensitive to mechanical stimulation i.e., membrane tension. Basu and Haswell review mechanosensitive…

It’s not uncommon for viruses to manipulate the host’s membrane system to create protected structures for viral replication. These viral replication complexes (VRCs) “are thought to shield viruses from host defense systems such as RNA silencing, and … provide a microenvironment for enriching…

FRET-FLIM (Fluorescence Resonance Energy Transfer – Fluorescent Lifetime Imaging Microscopy) is a method that allows detection of interactions between two fluorescently-tagged molecules. Camborde and Jauneau et al. describe the use of FRET-FLIM to identify interactions in leaves between GFP-tagged…

The relationship between plants and arbuscular mycorrhizal fungi has persisted for 400 million years, but we are still learning about the biochemistry of this interaction. MacLean, Bravo and Harrison review how plants attract, recognize, and accommodate their fungal partners, from pre-contact through…

Chloroplast biogenesis and leaf development are closely linked processes that have been difficult to tease apart, until recently. Dubreuil et al. used a pluripotent inducible cell line from Arabidopsis, basically plant stem cells, which develop chloroplasts on demand when exposed to light. Using this…

Fungal invasion exploits plant cell membrane trafficking components. For instance, plant immunity against fungi such as Vlumeria graminis f.sp. hordei (Bgh) is defined through two stages: pre- and post-invasive immunity. Nielsen et al. found that Vacuolar Protein Sorting 9a (VPS9a) acts as a guanine…

ARMADILLO-REPEAT KINESIN 1 (ARK1) promotes microtubule disassembly and NIMA-RELATED KINASE 6 (NEK6) organizes microtubule arrays. Previous studies showed that NEK6 interacts with ARK1 through Armadillo-repeat (ARM) cargo domain. Eng et al. looked at two constructs: one which lacks ARM (ARK1▲ARM-GFP)…

A plant’s life begins with the fusion of haploid egg and sperm cells to produce a diploid zygote. Many of the processes that control early development are under the control of the maternal genome, but at some point there is a shift towards zygotic control. Chen et al. investigated when this shift occurs…

Two reviews in the Journal of Experimental Botany provide updates about protein secretion from plant cells. Wang et al. (10.1093/jxb/erx262) describe the conventional and unconventional pathways of protein secretion.  The conventional pathway for protein secretion starts with insertion of the nascent…

Guard cells are crucial gatekeepers that control entry and exit of gases, water vapor, and pathogens. Rapid stomatal pore closure in response to pathogen perception or the hormone abscisic acid (ABA) is supported by activation of the aquaporin (water channel) PIP2;1. Rodrigues et al. investigated the…

Calcium (Ca2+) is an important cellular second messenger for diverse developmental processes and environmental responses in both plants and animals. Transient increases in cytosolic Ca2+ are activated in plants during a host of environmental and developmental processes, including root growth, stomatal…

New reviews cover the hot topic of membrane and vesicle trafficking in plant immunity.  Gu et al. (Mol. Plant 10.1016/j.molp.2017.07.001) provide an overview of the two membrane trafficking pathways: the secretory pathway involved in movement of antimicrobials, defense proteins and cell wall components…

Saffer et al. identified an Arabidpsis mutant with swirled petals and with petal epidermal cells that show a left-handed (but never right-handed) twist. They mapped the mutation to the RHAMNOSE BIOSYNTHESIS1 (RHM1) gene, which is most highly expressed in petal epidermal cells and encodes an enzyme that…

It’s easy to demonstrate that plants sense gravity, and we also know that statocytes are involved in the perception of gravity. Statocytes are gravity-sensing cells that contain dense starch-containing amyloplasts that move within the cell in the direction of gravity. Differential growth to accommodate…

Hu et al. found a sterile rice mutant defective in meiosis. They mapped it to MEICA1, a widely conserved but uncharacterized protein required to ensure crossovers occur between allelic regions of chromosomes. It also inhibits allelic homologous recombination. This adds to a suite of proteins eukaryotic…

Calcium signalling is a ubiquitous process in plants and other organisms. Transporters at the plasma and vacuolar (tonoplast) membranes control entry and exit of calcium ion into the cytoplasm, and it is the cytoplasmic calcium level ([Ca2+]cyt) that affects cellular responses, as calcium-binding proteins…

Following double fertilization, the embryo and the endosperm form within a developing seed. In Arabidopsis, the endosperm is somewhat transient, as most of the space it occupies is eventually taken over by the embryo. The question of how the embryo pushes aside the endosperm has not been fully clear.…

Bacterial effectors are proteins produced by bacteria and introduced into their hosts, where the effectors support successful infection by the pathogen. Effectors can function in diverse cells and cell compartments, but many studies of effector localization have relied on overexpression systems which…

Plasmodesmata are pores between cells through which viruses, proteins, small RNAs and other molecules can pass. The pores are usually described as being lined with a layer of plasma membrane with a tube of endoplasmic-reticulum membrane through the center. These membranes and associated proteins are…

The waxy cuticle, a key barrier to desiccation and pathogen entry, is a dynamic structure, the composition, area, permeability and thickness of which can change in response to environmental conditions.  For example, water deficit in Arabidopsis (Arabidopsis thaliana) triggers an increase in the accumulation…

Throughout plant life cycle, from germination till reproduction, every event is regulated by a highly complex network of hormones. Unlike animals where hormones are synthesized in specific glands, each plant cell is able to produce hormones. However, hormones are synthesized in specific organs in plants.…

Eukaryotic pathogens are responsible for devastating plant diseases that threaten food supplies globally – think potato blight caused by the oomycete Phytophora infestans, rice blast caused by the fungus Magnaporthe oryzae, and wheat stem rust caused by the fungus Puccinia graminis f. sp. tritici.…

SPA (SUPPRESSOR OF PHYTOCHROME A-105) proteins form a complex with COP1  (CONSTITUTIVELY PHOTOMORPHOGENIC 1) and are required for COP1 to respond to changes in the light environment and transduce light signals and influence plant development. In this paper, Balcerowicz et al. investigated the importance…

Chloroplasts have evolved from photosynthetic bacteria, and genes necessary for chloroplast function have moved from the chloroplast to the nuclear genome of the host eukaryotic cell.  Proteins encoded by these genes are made in the cytosol and imported into the chloroplast using protein translocases. …

RxLR effectors are proteins secreted from pathogens that enter the cells of the host and support the effectiveness of the pathogen in various ways. Their name refers to the sequence RxLR (Arg-Xxx-Leu-Arg). Previously, this sequence has been thought to be involved the effector’s entry into the host…

Many agricultural lands are becoming saltier as a consequence of irrigation and sea water incursion, yet most crops are very sensitive to salt. Salt glands that accumulate and secrete salt have evolved independently at least 12 times in plants. Dassanayake and Larkin review the structure, function and…

Soon after dicots germinate, the hypocotyl arches into a hook-like structure that protects the shoot apical meristem as the seedling grows through the soil. Once the seedling emerges from the ground and senses light, the hypocotyl straightens. The asymmetric growth that results in apical hook formation…

Regulated movement to and from the plasma membrane (PM) has emerged as an important strategy for controlling the activity of plasma membrane proteins such as transporters and receptors. Jonsson et al. investigated the cellular machinery required for the insertion of the auxin-transport protein AUX1 into…

How do stomata open in response to blue light?  Blue light is perceived by phototropin receptor kinases that activate BLUE LIGHT SIGNALING1 (BLUS1), type 1 protein phosphatase (PP1), and the plasma membrane (PM) H+-ATPase.  Hayashi et al. screened a commercial kinase inhibitor library to identify the…

Cell walls are complex mixtures of cellulose microfibrils, proteins and other materials. Their mechanical properties can be measured and modeled, but it is not always simple to translate these measurements to changes at the molecular level. Zhang et al. used atomic force microscopy to provide an unprecedented…

Cell size is determined by growth rate and frequency of division. Studies in yeast revealed mechanisms that coordinate these processes, as well as the crucial checkpoint controls that ensure the cell is “ready” to divide, but can models from single-celled organisms be applied to multicellular ones…

A pair of Breakthrough Technology papers in Plant Physiology discusses new tools to identify hydroxyproline-rich glycoproteins and insights into their evolution. Hydroxyproline-rich glycoproteins (HRGPs) are repeat-rich cell wall proteins that have been described as falling into three large families:…

Border cells form at the root tip and are shed during growth, protecting the sensitive root apex from damage as it pushes through the soil. Mravec et al. investigated the cell wall chemistry, carbohydrate distributioion and expression of cell-wall modifying genes to determine the mechanism by which border…

Brassinosteroid (BR) signaling promotes growth and development by regulating gene expression through the BES1 and BZR1 transcription factors.  Nolan et al. show how plants balance growth and stress tolerance by cross-talk between the BR and autophagy pathways. Under environmental stresses, BES1 is targeted…

Every student of plant cell biology learns that the future plane of cell division is marked very early in mitosis by the preprophase band (PPB), a band of microtubules that forms around the periphery of the cell. Prior experimental studies have suggested that the PPB is necessary for proper placement…

Proteins carry sequence tags that are read by cellular machineries that deliver the proteins to their proper destinations, which include the nucleus, mitochondria and plastid. Many pathogen effector proteins have acquired such targeting tags too, but for these can sometimes be cryptic to bioinformatics…

The unfolded protein response (UPR) is a eukaryote-wide signalling pathway in which unfolded proteins in the ER (often caused by abiotic stress) initiate signals transduced to the nucleus that lead to the expression of stress-response genes. Bao and Howell review the UPR in plants. They describe two…

NRAMPs are transporters of iron (Fe) and manganese (Mn). The nramp3nramp4 double mutant arrests shortly after germination, due to its inability to remobilize Fe from seed vacuolar stores. Agorio et al. used a genetic approach to identify nns1, a partial suppressor of the growth-arrest phenotype. They…

Light sheet fluorescence microscopy (LSFM) is a powerful imaging tool; unlike confocal microscopy, which illuminates a sample one small volume at a time, LSFM illuminates a complete optical section at a time, greatly speeding up the imaging process and lowering phototoxic effects. Candeo et al. use close-to-physiological…

Both receptor-like protein kinase (RLK) and reactive oxygen species (ROS) signaling have been shown to affect a plethora of plant processes, including growth, metabolism,  development, and environmental responses. To date, previous reviews have focused on mechanisms that govern either ROS or RLK signaling;…

Gas exchange and transpiration are regulated by the stomatal aperture, which is itself regulated by the changes in volume of the guard cells that overlay the stomatal pore. When triggered to open, solutes such as K+ and Cl– enter the guard cell through ion transporters, followed osmotically by water;…

Waterlogging, a process by which water saturates soil, results in oxygen-deficient soil conditions and can result in massive crop loss. In order for plants to survive in waterlogged soil, shoots transport oxygen to roots through lysigenous aerenchyma, a specialized tissue type formed by ethylene-induced…

Although plant cells are surrounded by walls, cytoplasmic strands connect adjacent cells through junctions called plasmodesmata. Liu et al. investigated the contributions of plasmodesmata to signaling between root quiescent center (QC) cells and the cells that surround the QC by expression of an inducible…

Green Fluorescent Protein (GFP) is a widely-used reporter with which to analyze protein localization and expression levels. De Jonge et al. report that GFP fluorescence is greatly diminished in the presence of the hormone salicylic acid (SA), as is the fluorescence of the reporters RFP and VENUS. The…

Monitoring cells and their activities in real time provides exceptional insights into their mechanisms and strategies of growth. Prunet has used live confocal imaging of Arabidopsis flowers to study the placement of floral organs and the dynamics of floral stem cells. Here, he presents a detailed protocol…

IN BRIEF by Jennifer Lockhart [email protected] Plant cell components that are no longer needed are degraded in the vacuole, but they don’t get there by magic. Sack-like double-membrane structures called autophagosomes engulf this cellular rubbish and neatly transport it to the vacuole for degradation.…

Plants breathe through pores called stomata on leaf surfaces. Stomata are the point of contact with the outside world as they allow gas exchange (e.g., CO2 for photosynthesis) and transpiration. Grasses have evolved to form more efficient stomata in which the guard cells are flanked by additional subsidiary…

Casparian strips, named after the German botanist Robert Caspary who discovered them, are a cellular feature found in the roots of all higher plants. They are ring-like lignin polymers deposited in the middle of anticlinal cell walls (parallel to the root radius) between endodermal cells. Along with…

This article was originally published on The Conversation. Read the original article. By Kevin M. Folta, University of Florida   Driving down a country highway in the Midwest can seem an endless ribbon flanked by green walls of corn, neatly planted in stately rows. But who would guess…

Plant hormones are active at very small quantities and often act differently in different cell types. Various methods, primarily involving mass spectrometry and sensors, have been developed to identify and quantify hormones with cellular-level precision. Novák et al. review these methods and discuss…

Calmodulin (CaM) and closely related CaM-like polypeptides are principal sensors of Ca2+ signals. The plant-specific IQ67 DOMAIN (IQD) family has emerged as possibly the largest class of CaM-interacting proteins with undefined molecular functions and biological roles. Bürstenbinder et al. (Plant Physiol.…

When a pathogen is perceived, plants have the ability to induce stomatal closure to prohibit the pathogens from passing into the inner tissues; this response is known as stomatal immunity. Two new papers in The Plant Cell investigate mechanisms by which pathogen perception is transduced into stomatal…

It is well known that long distance transport and movement of molecules is enabled by phloem, but the precise mechanism of loading/unloading of phloem mobile compounds is not known. In this article, Ross-Elliott et al. used a combination of approaches (non-invasive imaging, 3D-electron microscopy, and…

Xa4 is a durable rice disease resistance gene that confers resistance against Xanthomonas oryzae pv. oryzae (Xoo), causal agent of bacterial blight. Hu et al. show that Xa4 encodes a wall-associated kinase (WAK) that promotes cellulose synthesis and suppresses wall loosening, thereby strengthening the…

Stomata, epidermal pores for gas exchange, first appeared about 400 million years ago. Since then, there has been functional and structural diversification. Qu et al. synthesize the developmental genetics underpinning diverse stomata, spanning from bryophytes through monocots and the astomatous (without…

It’s easy to visualize how a sheet of cells grows, but how does a sheet of cells form a complex, three-dimensional structure? Rebocho et al. describe how differential growth rates between cell layers and across the growing surface can produce a variety of complex shapes. As a model for shape complexity,…

The other day I was talking to a friend about the need to demystify plants, so that teachers feel as confident in their teaching of plant biology as they do about animal biology. I wonder if sometimes we teach plants too much in isolation, so it’s not always clear how plants relate to other organisms…

IN BRIEF by Gregory Bertoni [email protected] Autophagy, or "self eating," is the process cells use to consume unwanted intracellular structures such as damaged organelles, excess membranes, and unneeded cellular proteins (Mizushima and Komatsu, 2011). Typically, the unwanted structure becomes surrounded…

Autophagy is the process by which macromolecules and organelles are recycled. Previously it was shown that during leaf senescence or energy starvation, chloroplasts are degraded piecemeal by autophagy. In this work, Izumi et al. examined the role of autophagy in UVB damaged chloroplasts, using wild-type…

Laser capture microdissection (LCM) was developed 20 years ago as a way to isolate single cells or clusters of cells for subsequent –omic analysis.  In LCM, thin sections are generated, the cells of interest cut out using a focused laser, and the isolated cells collected for subsequent studies. Several…

Phosphorus (P) is a non-renewable soil nutrient essential for plant growth. The vacuole serves as a crucial dynamic store of P that helps maintain cytosolic homeostasis. Yang et al. review vacuolar P stores, comparing P storage species and membrane proteins in yeast, algae and plants. In yeast, polyphosphate…

IN BRIEF by Jennifer Lockhart [email protected] The interior of a plant cell is supported by the actin cytoskeleton, a complex network of yarn-like fibers whose form changes as the cell develops, grows, and divides. Actin fibers readily come apart (sever) and join back together, depending on the…

The Casparian strip is a permeability barrier that seals the spaces between root endodermis cells and so prevents bulk-flow uptake of solutes. Previously, a leucine-rich repeat receptor kinase called SCHENGEN3 or GASSHO1 (GSO1/SGN3) was identified as necessary for normal Casparian strip formation. Now,…

Plants use light as a source of energy and information; however, they are also sensitive and respond to  light/dark diurnal cycling, with many processes happening during the dark phase of the diurnal cycle. In this review, Seluzicki et al. emphasize the importance of studying and understanding what…

IN BRIEF: Nancy R. Hofmann [email protected] Plant development and responses to the environment hinge on the ability to target proteins to different areas of the plasma membrane within a cell. Indeed, the establishment of polar distributions of proteins such as PIN auxin transporters is among the…

A seed undergoes a dramatic transformation from dried tissues into a mature plant.  This change requires energy produced by oxidative metabolism, but dry seeds contain dormant promitochondria that need to be reactivated.  Paszkiewicz et al. use bioimaging tools for an in vivo analysis of seed mitochondria…

Students learn that membrane proteins are inserted into the endoplasmic-reticulum (ER) membrane co-translationally, but this mechanism does not hold for so-called tail-anchored (TA) proteins which carry a single C-terminal membrane spanning domain and insert into the ER membrane post-translationally.…

Root architecture and anatomy contribute to water uptake efficiency and plant performance under water-limitation. Prince et al. explored root anatomy in a panel of soybean, and identified metaxylem number as a key trait influencing performance under water-limiting conditions. Increases in metaxylem number…

Autophagy is a process of selective membrane trafficking that delivers cargo to the vacuole or plasma membrane for recycling or secretion. ATG8 is a small ubiquitin-like protein that is required for formation of the double-membrane enclosed autophagy vesicle, the autophagosome. The ATG8 gene family has…

IN BRIEF by Kathleen L. Farquharson [email protected] Limiting shoot growth is an important survival strategy for plants during times of drought; smaller leaves mean that less water is lost through transpiration and more is retained in the soil. As drought stress restricts both cell division and…

Aluminum (Al) toxicity is an important agricultural problem, limiting crop production globally. Al toxicity causes a reduction in nutrient uptake, resulting in nutritional deficiency and leading to an overall reduction in shoot biomass and crop yield. Eekhout et al. discuss Al toxicity and strategies…

The autophagosome, a cellular compartment involved in the turnover of macromolecules, contributes to nutrient homeostasis, stress resilience and defense. Although several proteins have been identified as contributing to autophagosome formation and function, the precise origins of the autophagosome have…

The rice blast fungus Magnaporthe oryzae causes a devastating disease of rice that can reduce harvests by 30%. Infection of plant tissues by the fungus requires the formation of an appressorium, a specialized structure that builds up sufficient pressure to burst through the plant cuticle. Previous work…

The AVP1 gene encodes a proton-pumping pyrophosphatase (H+-PPase) localized to the vacuolar membrane, which means that it pumps H+ into the vacuole using energy stored in pyrophosphatase (PPi). The direct consequences of its action are the acidification of the vacuole and the removal of PPi from the…

The Journal of Experimental Botany has a special issue on vascular development that features several outstanding review and opinion articles. Topics include Evolution of Conducting Cells, Regulation of Vascular Cell Division, overviews of hormones, peptide signals, receptors and transcription factors…

A pair of reviews in J. Exp. Bot. covers aspects of seed dormancy and germination. Steinbrecher and Leubner-Metzger (10.1093/jxb/erw428) provide an excellent introduction to materials science including stress-strain curves and Young’s Modulus, which they then apply to an understanding of the biophysics…

A germinated pollen grain extends a pollen tube through the stigma and style of the flower to deliver two sperm cells to an ovule.  Tip-directed growth of the pollen tube requires a large energy input, but how does the pollen tube obtain energy while growing through the flower tissues?  Goetz et al.…