Tag: Physiology

Cassava (Manihot esculenta) is a vital starchy crop essential for food security in Sub-Saharan Africa, South America, and Southeast Asia. A recent study on cassava by Rüscher et al. provides important insights into the plant’s sugar control mechanisms as the roots expand, produce large amounts of…

Photosynthesis is the process by which plants assimilate carbon by using light energy. However, with the solar energy conversion efficiency of many crop plants less than 1%, it is inefficient. Therefore, there is interest in manipulating photosynthesis for increased efficiency. Here, Croce et al. identifying…

Throughout the plant science community, the use of computational or in silico analyses which precede traditional studies are gaining traction to identify research opportunities. Multiscale computational models are those which assimilate data from all biological system levels from gene to ecosystem. Benes…

Mitochondrial metabolism provides ATP and reducing power to drive myriad reactions in the plant cell, and is constantly being fine-tuned in response to environment and demands. Post-translational modifications (PTMs) of proteins, including redox reactions of methionine and cysteine and carbamylation…

Guard cells are extremely sensitive and dynamic, and their behaviour controls rates of gas exchange and transpiration, which affect evaporative cooling and transport in the xylem. Matthews et al. review the roles of light signalling pathways in guard cell responses. Cues that control guard cell ion channels…

Deficit irrigation is water-conserving strategy in which a growing plant is given just enough but never too much water. Previous studies have shown myriad physiological changes caused by deficit irrigation including decreased growth rate and shoot:root ratio, and also a lower fruit water content. Here,…

Plants have a remarkable ability to coordinate cellular activities across huge distances, yet we have only a basic understanding of how these remote activities are coordinated. A review by Rodrigues et al. summarizes what we know about the relationship between source (e.g., photosynthetic tissues) and…

Identifying methods to improve crop productivity is vital considering the devastating consequences of climate change (e.g., frequent droughts). Stomatal conductance influences photosynthesis and water use efficiency, which are two important indicators of crop yield. Here, Faralli et al. discuss advances…

The year 2019 kicks off with a special issue on root biology, with all articles free to access for six months. Topics include interactions of roots with parasites and symbionts, root branching, transport in the root system, and roots of woody species. (Summary by Mary Williams) Physiologia Plantarum…

Cryptochromes are a class of flavoproteins found in plants and animals that are sensitive to blue light. In Arabidopsis, cryptochromes are involved in many important physiological processes including de-etiolation, flowering, circadian rhythms, cotyledon opening and expansion, anthocyanin accumulation,…

Assessing the effect of rising CO2 concentrations on plant growth and physiology traits is crucial in order to determine how ecosystems and crop production systems will perform in future climates.  Such assessments have been made with free-air CO2 enrichment (FACE) experiments, which have provided a…

Senescence in plants is a prelude to cell or organ death. The metabolites and macromolecules released during senescence are salvaged by the plant for use elsewhere. Generally, senescence occurs prior to programmed cell death (PCD), since the characteristic leaf yellowing can be reversed while PCD is…

Zheng et al. reveal that plant endogenous peptides and their receptors initiate stomatal closure to prevent microbes’ entry, thus enhancing plant immunity. The Plant Cell (2018) https://doi.org/10.1105/tpc.17.00701. By Xiaojiang Zheng and Sheng Luan. Background: Unlike animals, plants can’t…

Koskela and Brünje et al. identified a chloroplast protein acetyltransferase, which is required for the regulation of light harvesting in Arabidopsis. Plant Cell (2018) https://doi.org/10.1105/tpc.18.00155. by Minna M. Koskela, Annika Brünje, Iris Finkemeier, Paula Mulo   Background: Plants…

The humble spud. Simple, unassuming, yet vital in supporting a large proportion of the world’s population. Historically speaking, much of the research performed on potatoes (Solanum tuberosum) has gone into enhancing their disease resistance, justifiably so given the severe famines brought about through…

High-throughput plant phenotyping systems are an excellent tool for analyzing large plant populations, providing better understanding of plant growth, productivity and performance under stress conditions. Unfortunately, high-throughput platforms are also high on costs and limited in their adaptability…

Surprisingly little is known about the pathogens of liverworts. Carella et al. explored the interaction between the broad-host range pathogenic oomycete Phytophthora palmivora and the model liverwort Marchantia polymorpha. They found that the pathogen enters the host tissues and proliferates in intercellular…

Land plants evolved from freshwater charophyte algae over 450 million years ago and have since diverged into the multitude of plant lineages observed today. The extent to which prominent plant hormones and cognate receptor proteins, which play essential roles in evolutionarily young angiosperms, are…

Polyamines, which include putrescine [NH2(CH2)4NH2], spermidine [NH2(CH2)4NH(CH2)3NH2], and  spermine [NH2(CH2)3NH(CH2)4NH(CH2)3NH2], are widespread in nature. Although their mechanisms of action remain largely unresolved, they have demonstrated roles in plants ranging from abiotic stress tolerance…

Plant growth is regulated seasonally, but our knowledge is limited about how their growth is inhibited or re-initiated seasonally. Looking at hybrid aspen, in this article, Tylewicz et al. explored how seasonal cycles of growth and dormancy help perennial plants adapt during winter. In the long days…

The phytohormones jasmonic acid (JA) and salicylic acid (SA) play key roles in how plants respond to microbes. However, this interplay between JA, SA and microbes is less understood in non-angiosperm linages. de Vries and colleagues examine JA/SA signalling between the water fern Azolla filiculoides…

C4 photosynthesis describes a biochemical CO2-concentrating mechanism that relies on the spatial separation of biochemistry between two cell types, mesophyll cells (MCs) and bundle sheath cells (BSCs). However, there is currently little evidence on how some genes are preferentially expressed in BSCs…

The activation of photosynthetic electron transport upon a dark-to-light transition occurs prior to the initiation of CO2 fixation by Rubisco in the Calvin cycle.  A mechanism known as cyclic electron transfer (CET) exists that generates the proton motive force required to drive ATP synthesis without…

The assembly of the carbon fixing enzyme Rubisco is a complex process and involves many chaperones including RAF1, RbcX and the chaperonins. Recent evidence pointed to the existence of another chaperone, RAF2, conserved among photosynthetic organisms. The protein has similarity to pterin-4α-carbinolamine…

PLOS Biol. Guard cell size is, in general, inversely related to stomatal density. It is advantageous for plants to maximize their photosynthetic capabilities by generating higher rates of gas exchange, thereby incorporating more CO2 to help drive this pathway. However, the number of cells that can occupy…

Although reactive oxygen species (ROS) have historically been considered damaging agents within cells, recent studies have demonstrated that these molecules also serve as second messengers in signaling pathways. The reactive nature of ROS allows these compounds to function as signaling molecules by reversibly…

When the vapor pressure difference (VPD) between a leaf and the atmosphere increases (i.e., when air humidity decreases), guard cells lose turgor, thereby leading to stomatal closure. The evolution of this mechanism was an important step in the colonization of land by plants, since it enabled plants…

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…

Desiccating leaves show increased ABA levels triggered by low turgor – right? Apparently not! The pressure chamber experiments showing increased ABA levels in desiccating leaves are inconsistent when the entire leaves are enclosed in the chamber. Sack et al. proposes that the turgor pressure is increased…

If you whithold water from a plant it eventually will wilt, but before this visible change there are other measurable effects and responses. However, many plant processes change cyclically over a 24-hour period independently of early drought responses, so it can be difficult to separate drought-responsive…

Plant shoot branching is determined by apical dominance, a process in which the apical bud (shoot tip) inhibits the outgrowth of axillary buds further down the stem to control the number of growing branches. In response to this inhibition, plants have evolved rapid long-distance signaling mechanisms…

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…

Browsing the table of contents of the “The Making of a Plant” special issue of Current Biology feels like a birthday celebration; there are so many exciting goodies it’s hard to know which to open first. The issue consists of well-written and well-illustrated short reviews (and Quick Guides and…

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…

Many plants living in arid environments conserve water by taking up CO2 at night through the action of the enzyme phosphoenolpyruvate carboxylase (PPC); this process, which is widespread in the Crassulaceae family, is known as Crassulacean acid metabolism (CAM). The nocturnal activity of PPC is regulated…

Much of our understanding of the molecular processes of senescence and nutrient remobilization comes from annual plants. Yang and Udvardi explore how these processes take place in perennial grasses including important biofuel grasses switchgrass (Panicum virgatum) and miscanthus (Miscanthus×giganteus).…

The October issue of Current Opinion in Plant Biology includes several articles that review various topics on the subject of plant nutrition. These span the spectrum of nutrients from trace and metal nutrients to macronutrients. The reviews also span topics such as membrane and tissue-level transport,…

Sugars produced in photosynthetically active mesophyll cells move into the phloem through a process known as phloem loading, but not all plants phloem load the same way. Some use a passive process in which sugars move down a concentration gradient into the phloem, but others use active transport processes.…

Improving photosynthetic efficiency is a major target for increasing crop biomass production and yield potential. The canopy photosynthetic efficiency, which is determined by leaf area index, canopy architecture, and leaf photosynthetic properties, plays an important role in determining biomass accumulation.…

Nitrogen (N) is an essential nutrient that plants require in large amounts for growth and development. In industrial countries, high N fertilization enables maximum crop yields, and in the last 50 years, the use of synthetic N fertilizers has increased dramatically to meet food demands. Improving the…

In order to address the knowledge gap in the mechanisms of photoperiodic induction of flowering by phytochrome, Pearce et al. studied flowering behavior in wheat grown under short days, with the interruption of the long nights by short pluses of light (night breaks). Their study showed that night breaks…

Animals and plants have divergent sets of blue light receptors, called Cryptochromes. However, green alga Chlamydomonas has both animal-like and plant cryptochrome (pCRY). The presence of multiple cryptochrome suggests specific roles in different pathways in respective organisms. In this paper, Müller…

Iron is an essential nutrient that plants assimilate from the soil. Moderate iron deficiency induces an increase in primary root length and lateral root production. Satbhai et al. examined natural variation of root responses and showed a correlation between root length and allelic variation at the FRO2…

Phosphate is both really important (think of its abundance in DNA, RNA, ATP, and membrane lipids), and really difficult to assimilate due to its insolubility and immobility in soil. Phosphate is frequently limiting for growth, meaning that it is widely applied as fertilizer, but global supplies of phosphate…

Salinity is a growing problem for food production. Progress has been made in understanding how plants tolerate salinity, mostly focused on strategies for tolerance at the plasma membrane and cytosol. Bose et al. review studies that focus on how the chloroplast is affected by salinity. The authors review…

Transporters are massively important for the functions of a cell and organism, but also notoriously difficult to study. Larsen et al. review advances in the tools available for transporter research, ranging from expression in Xenopus oocytes to genetic screens using toxic analogues and fluorescent substrates,…

Plants and seeds are the main dietary source of essential micronutrients in the food chain. The processes regulating transport of micronutrients to and within seeds are critical for germination and enrichment of seeds. Metal transport protein 8 (MTP8) has been characterized as a tonoplast Mn transporter…

Photosynthetic capacity varies hugely within an individual over time, between individuals in different environments, and between species. Demming-Adams et al. review the processes that affect intrinsic photosynthetic capacity. Plants modulate their intrinsic photosynthetic capacity according to input…

Sugar is a signal as well as an energy source, and plants monitor sugar levels to maintain an appropriate growth rate and rate of photosynthesis. A new study by Kelly et al. points to a role for sugars in the expression and activity of plasma-membrane (PIP) aquaporins. Aquaporins (AQP) are membrane channels…

Potato is an important food crop, but unlike most of the other major foods, it is a tuber, not a seed. Classic studies showed that there is a mobile, photoperiod-induced signal that moves from the shoot to the stolen tip (an underground, stem-like structure) to initiate tuberization. Experimental studies…

Stomatal control of transpiration is critical for maintaining important processes, such as plant water status, leaf temperature, as well as permitting sufficient CO2 diffusion into the leaf to maintain photosynthetic rates (A). Stomatal conductance (gs) often closely correlates with A and is thought…

“Succulence is a phenomenon that has long eluded a decisive consensus definition,” begins Males in his review of the physiology and evolutionary developmental biology of succulence. Succulence can broadly be defined as the storage of water such that the plant can maintain physiological activity in…

Ammonium is one of the major forms in which nitrogen is assimilated. Besides being a nutrient, it also acts as signal that affects gene expression and root system architecture. Some ammonium-induced genes are also induced by low pH (ammonium acidifies the apoplast), whereas others are specifically induced…

To balance nutrient uptake (usually from heterogeneous sources) with nutrient demand, plants use a root-shoot-root signaling pathway. Previously, a root-to-shoot mobile peptide C-TERMINALLY ENCODED PEPTIDE (CEP) was shown to translocate from N-starved roots to the shoot, where it interacts with a leucine-rich…

In leaf mesophyll cells, some of the sugars produced by photosynthesis are stored as transitory starch, which is then broken down to provide the cells with energy during the night. Recent advances in imaging and staining and the use of mutants have enabled the pattern of accumulation of transitory starch…

In photosynthesis, light energy generates proton motive force (pmf) across the thylakoid membrane. The establishment and maintenance of pmf involves numerous membrane transporters as well as other ions.  Szabò and Septea review how various ions (including K+, Na+, Fe2+, Cu+, Mn2+, Ca2+, Cl–) contribute…

Large-scale phenotyping efforts depend on large numbers of measurements, so the time taken for any one measurement has a big effect on the number of samples that can be processed. Stinziano et al. describe a breakthrough in the method used to identify the photosynthetic parameters Vc,max  (maximum rate…

With populations increasing globally, improving crop yield potential is one of the major challenges to the plant biologist, complicated by the changing climate. A better understanding of the source (material producer or exporter, e.g., leaves) – sink (material importer or consumer, e.g., roots, growing…

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…

The classic art of plant breeding involves carefully examining a genetically segregating population for traits of interest. Increasingly, high-throughput, automated phenotyping systems are being used; for example, robots can carry plants to imaging chambers for data collection. However, growth-chamber…

The distribution of metabolites in tissues can be determined in situ through the technique Mass spectrometry imaging (MSI) with matrix-assisted laser desorption ionization (MALDI) (also known as MALDI-MSI). Duenas et al. used MALDI-MSI to analyze the distribution of thylakoid membrane lipids in maize,…

Crassulacean acid metabolism (CAM) plants open their stomata at night, decreasing water loss and increasing water-use efficiency as well as drought tolerance. Males and Griffiths review the stomatal biology of CAM plants as compared to C3 plants. For example, CAM stomata are relatively insensitive to…

Chemical genetics is an approach that enables small molecules with specific effects on phenotypes to be identified. Through a screen for small molecules that would reverse the inhibitory effect of ABA on seed germination, Ye et al. identified AA1 (ABA Antagonist 1). AA1 interferes with the interaction…

Hypoxia is a condition in which oxygen availability is insuffient to support normal cellular functions. Hypoxia is often associated with stress such as flooding, and responses to hypoxia include increased glycolytic activity and fermentation. Considine et al. review the role lf hypoxia and tissue oxygen…

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…

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…

Legume nodules fix N, but their function has a high requirement for P, making nitrogen-fixation highly sensitive to P deficiency. Valentine et al. review how P limitation affects nodule function and also how nodules respond and adapt to P deficiency, drawing largely on studies of Virgilia divaricata,…

As a consequence of their ability to fix nitrogen in symbiosis with bacteria, legumes make key contributions to ecosystems and provide protein-rich foods for humans and other animals. Recent years have uncovered the nature of the signals involved in the cross-kingdom dialogues that occur between plant…

Chlorophyll has an aliphatic phytol side chain that anchors it to light-harvesting complexes. During senescence, chlorophyll is degraded first by the enzymatic removal of Mg to produce pheophytin, which is dephytlated by pheophytinase. Through the identification of a mutant allele with elevated enzymatic…

We’ve highlighted some of the Plant Cell papers that were widely shared, liked, blogged, retweeted and otherwise garnered high-levels of attention this year. Perhaps you can use some holiday-season quiet time to catch up on those you missed. Reviews and Perspectives Creating order from chaos: epigenome…

We’ve highlighted some of the Plant Physiology papers that were widely shared, liked, blogged, retweeted and otherwise garnered high-levels of attention this year. Perhaps you can use some of that holiday-season quiet time to catch up on those you missed. The breakaway attention-getter from Plant…

HAK5 is a high-affinity potassium transporter that is transcriptionally repressed in high K+ conditions. Zhao et al. identified hormone-related cis-elements in the HAK5 promoter. They screened mutants deficient in transcription factors associated with these cis-elements and found that arf2 mutants show…

Rubisco (Ribulose-1,5-bisphosphate carboxylase / oxygenase) is the enzyme responsible for fixing almost all inorganic carbon into organic form, but it is not optimized for current conditions. As temperature and CO2 levels increase, there is an opportunity to increase photosynthetic efficiency by engineering…

Crassulacean acid metabolism (CAM) is a specialized form of photosynthesis that greatly increases water-use efficiency by taking up CO2 through stomata that are open at night (when evapotranspiration is low). Engineering plants that can switch to CAM during periods of drought is a key goal towards…

Unravelling the mechanism and signals originating from roots and able to contribute to stomatal control has been the subject of research for decades. In this commentary, Tardieu summarizes and discusses many studies and models on root-shoot signals, including work in the same issue by Visentin et…