Tag: Transport and Transporters

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…

In the electrifying world of plant signaling, a paradigm shift is underway as researchers dig into the intricate mechanisms of action potentials (APs) and slow wave potentials (SWPs). Departing from conventional neurophysiological dogma in the animal kingdom, this review by Barbosa-Caro and Wudick illuminates…

Healthy plants require access to several mineral nutrients, which are usually taken up in ionic form. The details of nutrient uptake, distribution, and function have been painstakingly revealed over several decades. In this excellent new Tansley Review, Kunz et al. provide an overview of ion homeostasis…

If you’ve ever wondered how plants grow, survive, and adapt to their dynamic environment, the secret lies in their vast array of chemical messengers, also called phytohormones. Brassinosteroids  are important hormones that are crucial for plant development and defense against environmental stresses.…

Plant roots are functionally distinct along the longitudinal axis due to different cell types and diverse metabolic states. Root-secreted metabolites are involved in the assembly of complex microbial communities, yet the relationships between root-metabolites and organization of root microbiota at the…

Phosphorus (P) is an essential nutrient and critical component of nucleic acids, phospholipids, and other molecules. Yang et al. provide a historical (since 1996) overview of the processes controlling its uptake and use. Plants take up P from the rhizosphere primarily in the form of orthophosphate (Pi).…

What do you do when you’ve identified a gene that you know is important, but you don’t know how it functions? Usually, you can get hints from homology searches, overexpression studies, or the identification of protein domains, but sometimes those approaches don’t work. That’s where the story…

The earliest terrestrial plants had relatively small, simple forms. The evolution of water-conducting cells provided opportunities for increased size. However, water movement by tension (driven by evaporation) can fail when the water column breaks and is blocked by an air bubble called an embolism. Looking…

The development of vascular plants (tracheophytes) was a major innovation during the evolution of land plants. The classic view is that the evolution of transporting tissues is distinct to tracheophytes, but Woudenberg and Renema et al. discuss an alternative hypothesis where this was a gradual process…

Plants have evolved signaling cascades to survive biotic and abiotic stresses, and recent studies have shown that there is crosstalk between many of these pathways.  In a recent study, Dindas et al. developed a micro-electrode-based system to detect active inorganic phosphate (Pi) transport in Arabidopsis…

Lee et al. unravel a mitochondrial transporter responsible for selectively exporting citrate in exchange for malate. Plant Cell (2021) By Chun Pong Leea, Marlene Elsässerb, Philippe Fuchsb,c, Ricarda Fenskea, Markus Schwarzländerb, A. Harvey Millara aARC Centre of Excellence in Plant Energy Biology,…

Acidic soils often negatively impact plant growth, yet the application of fertilizers containing urea or ammonia have the effect of acidifying soils. In a recent paper, Ye and colleagues investigated how nitrate uptake through the nitrate transporter NITRATE TRANSPORTER 1.1 (NRT1.1) can mitigate some…

Plants possess a complex series of local and systemic signaling networks driven by multiple stimuli. They translate this information into plant-wide response to coordinate their physiology and development.  Here, Johns et al. review these communication pathways, which function across different scales…

Bacteria can exploit the stomatal pores to gain entry into plant leaves. Previous studies have demonstrated that guard cells close in response to flagellin, an effect that is described as stomatal immunity. Like ABA-induced stomatal closure, this involves the movements of ions and water from the guard…

N-1-naphthylphthalamic acid (NPA) inhibits polar auxin transport (PAT). Though used for over six decades, the precise mechanism by which it inhibits PAT is still unclear. A new study by Abas and colleagues now suggests that NPA directly associates with and inhibits the activity of PIN-FORMED (PIN) transporters.…

There’s been a lot of talk lately about how to improve the carboxylation efficiency of Rubisco, but of course this also depends on how much CO2 reaches the enzyme within the chloroplasts. To do so, it needs to pass through several distinct barriers: the boundary layer to reach the leaf surface, the…

Last week, PSRW presented two review papers regarding host plant interactions with microbial populations, particularly for plant nutrient intake. Watt-Williams et al. utilize such knowledge for their paper, performing an RNA-seq dataset to identify a novel zinc transporter in Medicago truncatula. Zinc…

In plants, the perception of environmental threats induces a peak of calcium ions (Ca2+) in the cytosol that triggers signal transduction pathways leading to stomatal closure as defense response. In Arabidopsis, the mechanosensitive Ca2+ channel OSCA1 regulates water transpiration in response to…

Floral architecture influences pollination and reproduction: open flowers facilitate cross-pollination, while closed flowers limit outcross. Some plants of the Leguminosae family (i.e., members of the Papilionoideae subfamily that includes soybean, pea, medicago, lotus) possess a complex architecture,…

Among all the mineral elements transported from the soil to the plant, cadmium (Cd) and arsenic (As)- are toxic for all organisms whereas 13 micronutrients, including iron (Fe) and zinc (Zn), are beneficial for both human and plant nutrition. Ideally, food crops should accumulate fewer soil contaminants…

In plants, stomata are involved in a host of responses, controlled by ion homeostasis in guard cells. In an attempt to understand the function of a plant chloride channel (CLC), CLCa, which transports chloride (Cl-) and nitrate (NO3-) in guard cells, Demes and colleagues sought to establish a relationship…

Optimal volume and turgor in the plant cell is important for metabolism, development and growth. Excessive diffusion of water into the cell will cause extreme swelling and a loss of cellular integrity. Members of the plasma membrane MscS-like (MSL) family of mechanosensitive (MS) ion channels play a…

Continuous agricultural production is required to feed the growing population, and fertilizers are important factors determining the productivity of today’s high-input agriculture. Fertilizers increase the cost of production, some are produced from finite sources, and some create environmental concern,…

In order to grow upwards into the dry atmosphere, plants need to keep their elevated tissues hydrated and functional. In vascular plants this is achieved by a lignified water transport system in conjunction with stomatal regulation of gas exchange and the encasement of photosynthetic tissues in an impermeable…

Adjacent cells in plants are connected by cytoplasmic connections called plasmodesmata (PD) and the movement through PD is called symplastic movement. Studies have shown that auxin transport between cells is protein-dependent, but it is not clear whether it can also move freely in the symplastic pathway.…

Aquaporins, also known as water channels, are conserved across all kingdoms. In plants, the plasma membrane intrinsic protein (PIP) subfamily controls membrane water permeability. Maize aquaporin PIP2;5 is highly expressed in roots. By reverse genetic approaches, Ding et al. showed that overexpression…

Roots anchor plants and take up water, but one of their most important and complex functions is to bring a large number of different essential nutrients into the plant. Root architecture affects and is affected by nutrient uptake, but ultimately uptake is largely controlled by membrane-bound ion transporters.…

ABA enhances stomatal closure and so decreases transpiration. Several studies have shown that increasing ABA levels can increase water-use efficiency, so this strategy has been investigated with the goal of obtaining “more crop per drop”. Lamarque et al. investigated physiological and hydraulic effects…

Potassium is one of the major nutrients for plant growth and development. Plants have a well-studied potassium uptake system mediated by transporters and ion channels. Unfortunately, due to the chemical similarity of potassium and cesium, which is toxic for plant growth, cesium is able to to get into…

Esca is a leaf scorch (necrosis) disease of grapevine that causes tremendous yield losses. Bortolami et al. have investigated the etiology of this condition, which is known to be a consequence of fungal pathogen infection. But how exactly does the fungal infection contribute to the observed symptoms?…

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…

Plants are equipped with multiple mechanosensitive (MS) ion channels that respond to external and internal mechanical perturbations. When one of these, AtMSL10, is overexpressed it leads to a cell death phenotype, although there is no discernible phenotype associated with its loss of function. Recently…

Manganese (Mn) is an essential plant nutrient necessary for multiple plant process such as photosynthesis. Mn deficiency has a significant impact on crop production particularly in cereals including barley (Hordeum vulgare L.). Chen et al. identified how Mn deficiency alters suberin deposition in the …

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,…

Indole-3-butyric acid (IBA) is the precursor of the hormone auxin and it controls the formation of lateral roots. Evidence suggests that IBA is converted to IAA, endogenous active auxin. The major study material to distinguish between IBA and IAA was highlighted by the IBA-specific efflux carrier ABCG36/PDR8/PEN3,…

Auxin activity is maintained through regulated biosynthesis, metabolism and transport. In this paper Jenness et al. characterized the physiological significance of a known IAA transporter, ABCB21 (ATP BINDING CASSETTE TRANSPORTER subfamily B member 21) in Arabidopsis. ABCB21 transports shoot derived…

Auxin transport regulated by directional transporters such as PIN (PIN-FORMED) proteins ensures maintenance of proper auxin levels for growth and development. Plants modulate auxin flow by regulating the localization of PIN through exocytosis and endocytosis allowing recycling of PIN protein within a…

Arsenic contamination is a growing human health threat. The fern Pteris vittata demonstrates a remarkable capacity to accumulate and sequester high levels of the toxic heavy metal arsenic from contaminated environments. Cai et al. used an ‘omics’-guided approach to identify and characterize the molecular…

Like other seed crops, wheat yields depend in part on the efficiency with which nutrients stored in leaves are mobilized into the developing seeds. This depends on the several processes from macromolecule breakdown to transport, as well as the timing of leaf senescence. Borrill et al. used RNA analysis…

Availability of nitrogen has always been a limiting factor for rice production. Different soil inhabitants and root-associated bacterial populations are involved in making nitrogen available to plants in organic as well as in inorganic forms. However, plant absorption of nitrogen is selective and affects…

If you haven’t been paying attention, you may have missed the great advances that have been taking place in xylem research recently. This excellent review by Brodersen et al. is your chance to catch up. Like all aspects of plant science, new tools and techniques have provided tremendous new insights…

Grafting is an ancient vegetative asexual plant propagation technique. It is characterized by the connection of two plant segments, the shoot piece known as ‘scion’ and the root piece called ‘rootstock’ or simply 'stock'. Grafting is widely used in agriculture to improve crop production and…

Iron is an essential nutrient for plants that participates in cellular processes such as DNA replication, photosynthesis, and respiration. Excess iron accumulation is harmful to plants due to its participation in the generation of reactive oxygen species, which can damage cellular machinery. One of the…

Plant activities change drastically between the light and dark times of day. Many of these different activities can be observed through transcriptional studies, which show that gene expression goes up and down over the course of the day. Many of these transcriptional changes are driven by the circadian…

Stomatal responses to environmental and endogenous signals in vascular plants are critical for regulating plant gas exchange with the atmosphere. In addition, stomatal closure is vital for minimizing water loss and preventing lethal embolism during drought.  The vast majority of studies concerning stomatal…

To compensate for their lack of a nervous system, vascular plants have developed complex mechanisms to connect their organs and coordinate stress. Many different types of molecules are involved in long-distance signaling and must be integrated to maintain homeostasis. In this review, Takahashi and Shinozaki…

Grafting is an ancient technology and still extremely important in horticulture and food production, including grapes for wine. Although much is known about what scion/shoot combinations work, less is known at the molecular and cellular level about successful grafts. How do two genetically different…

Wheat production demands huge inputs of nitrogen as fertilizer, with accompanying financial and environmental costs. Zorb et al. discuss several strategies by which to maintain wheat yields and wheat quality while decreasing N use and wastage. Some of these are agronomic, such as ensuring that the N…

Clubroot is a disease of brassicas (including oilseed crops and Arabidopsis) caused by the protist Plasmodiophora brassicae. The infection is characterized by the formation of swollen tissues called galls that are metabolic sinks in which the pathogen propagates. Walerowski et al. took advantage of Arabidopsis…

Background: Chloroplasts are the major powerhouse of plant and algal cells, where photosynthesis—the conversion of carbon dioxide into organic compounds using sunlight energy—occurs. Chloroplasts are also where important cell components (such as membrane lipids and pigments) and energy-rich compounds…

(Translated from the Chinese  original http://news.hzau.edu.cn/2018/1101/52991.shtml) Nanhu News Network (Correspondent Sheng Ke) On October 30th, the research group of Professor Tian Xingming from the Rice Science Team of the National Key Laboratory of Crop Genetic Improvement of our School…

Ammonium (NH4+) is an inorganic nitrogen source that is the preferred source for some plant species (e.g., rice and tea) but can be toxic in high amounts. The nitrate transporter NRT1.1 is involved in mediating the effects of toxic NH4+, as well as functioning in NO3- and auxin transport, NO3- signaling…

Of course plants need to communicate between their different parts, and our understanding of these crucial signals has been advancing rapidly. This issue of Plant Cell Physiology includes a set of papers highlighting recent findings. A meeting report by Kiba on the Integrative Graduate Education and…

Zinc is an important micronutrient for plants and people. To better understand Zn uptake and homeostasis, Sinclair et al. used a transcriptomic approach to identify genes abnormally expressed in zinc-transporter mutants (hma2 hma4). In these mutants, Zn accumulates in roots but isn’t effectively transported…

Going grocery-shopping on an empty stomach is a bad idea. You’re bound to make poor decisions, not based on nutritional content of the food but based on temporary cravings that will leave you asking for more later. Plants face this nutritional puzzle every day, since they eat where they shop, and shop…

In addition to hormones, proteins, and metabolites, many plants use mRNAs as mobile molecules for long-distance communication. It has been demonstrated that many mobile mRNAs are trafficked through phloem, probably by forming an RNA-protein complex to allow the stable translocation of mRNA molecules.…

Stomatal opening is stimulated by light, including blue and red light. Blue light-induced stomatal opening is fairly well understood: it is mediated by blue-light photoreceptor phototropins (phot1 and phot2). Blue light activates the plasma membrane (PM) H+-ATPase via phosphorylation of its penultimate…

The study of phloem transport and its vital roles in long distance communication and carbon allocation have been hampered by a lack of suitable tools that allow high-throughput, real-time studies. Since the 1970s, several studies have used 11C or 14C isotopes to measure rates of phloem transport in large…

Because local sugar concentrations play a critical role in regulating root growth, it is important to learn more about the mechanisms that control sugar transport into the growing zones of the 
root. It has previously been proposed that once translocated sugar reaches the interface between conducting…

The diploid strawberry (Fragaria vesca) is a useful model system for understanding non-climacteric ripening and seed-to-fruit cross-tissues communication. Previously, spatial and temporal transcriptome data from the strawberry fruit and flowers was generated. Shahan and colleagues combine the transcriptome…

Plant genomes encode many ATP-binding cassette (ABC) transporters, which mediate the transport of many different substrates involved in development, nutrition and stress responses. Mutants and transgenic plants have been used to understand the in planta roles, yet the identity of substrates transported…

Boron is an essential plant micronutrient with the narrowest optimal range in the soil of any micronutrient. At neutral pH, boron is present as uncharged boric acid, B(OH)3, which can freely penetrate membranes. Boron plays an important role in cross-linking cell wall components, but boron starvation…

Wang et al. investigate the function of OsNRT1.1A in rice. Plant Cell (2018). https://doi.org/10.1105/tpc.17.00809. By Wei Wang, Bin Hu and Chengcai Chu Background: To cope with an increasing global population and decreasing availability of arable land, improving crop yield is a major agricultural…

By Heven Sze and Salil Chanroj. Plants remodel their cells through the dynamic endomembrane system. Intracellular pH is important for membrane trafficking, but the determinants of pH homeostasis are poorly defined in plants. Electrogenic proton (H+) pumps depend on counter-ion fluxes to establish…

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…

Phloem has long been recognized as a tissue that transports carbohydrates and amino acids. In recent years, however, it has also been found that this tissue serves as a conduit for signals, e.g., mRNAs, small RNAs, proteins, small peptides, and hormones.  Several classical studies have shown that certain…

The one sure-fire way to get children excited about plants is to show them how a Venus flytrap works. But how does it work? We’ve all heard that the trap “counts” the number times it is triggered, and that it requires two or more touches in quick succession to close – but how does it count? Hedrich…

Iron is an essential micronutrient for plants but it is often not bioavailable in the soil. Thus, plants have evolved difference processes for iron sensing and iron uptake. OLIGOPEPTIDE TRANSPORTER 3 (OPT3) is an important iron transporter and is a component of the systemic network that mediates iron…

Plants need some but not too much iron, so the regulation of iron transporters is quite tight. IRT1 is a broad-spectrum metal transporter that is crucial for iron uptake (mutants can only be rescued by massive amounts of iron). IRT1 synthesis is transcriptionally upregulated by iron limitation, and although…

Iron, an essential nutrient for plants and symbiotic nitrogen-fixing bacteria, needs to be complexed with organic chelators (i.e. citrate) for in planta transport. Kryvoruchko and colleagues have identified a nodule-specific citrate transporter of Medicago truncatula, MtMATE67 (Medicago truncatula Multidrug…

Abiotic stresses such as drought, salinity, low temperature, and flooding usually lead to sugar accumulation. It has been reported that the accumulation of Glc, Suc, and Fru under high salinity plays an important role in carbon storage, osmotic regulation, and homeostasis, as well as scavenging of free…

The application of nitrogen-containing fertilizers is crucial for good yields of crops like rice but also is energy intensive and polluting, so many approaches are being explored to develop plants that are more efficient in their uptake and use of nitrogen. Previous studies identified a crucial role…

Approaches to improve final grain production must consider yield stability, that is ways to prevent yield losses. For example, flowering time affects yield and yield stability-- if grains mature late, they may be literally caught out in the cold, as late-season weather turns. Indeed, the application…

Viruses can move from cell to cell through plasmodesmata. Small interfering RNAs (siRNAs) are key components in the plant's arsenal against viruses. They function by harnessing the AGO system to target and cleave viral RNA, thus silencing the viruses. Like the viruses they target, siRNAs move from cell…

The corn smut fungus Ustilago maydis that causes tumorous symptoms on all aerial parts of maize has established itself as a model system to dissect host colonization strategies by biotrophic fungi. Transcriptional responses upon U. maydis colonization were previously demonstrated by several studies using…

Nature. Cuscuta sp. commonly known as dodder, is an obligate parasitic plant that colonizes a broad range of host plants and obtain water and nutrients by specialized feeding structure called haustorium.  Literature suggests that this specialized structure is involved in bidirectional movement of viruses,…

Boron (B) is an essential micronutrient for plant growth and development. Its major physiological function is to maintain the structure of the cell wall by crosslinking pectic polysaccharides through borate-diol bonding of two rhamnogalacturonan II molecules. B is immobile in most plant species. Therefore,…

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.…

Regulation of transcription occurs at the cell-type specific level, but transcribed messenger RNA is mobile and can move between tissues through plant vasculature, serving as a long distance messenger. Many mRNA molecules have been identified in the phloem sap, suggesting that mRNA transport goes through…

Wang et al. discover unexpected connections between humidity and ion transport using a model that bridges guard cell-to-leaf scales https://doi.org/10.1105/tpc.17.00694 By Maria Papanatsiou Background: Plants rely on stomata on the leaf epidermis for their survival. Stomata are small pores formed…

As a tree grows in height, increasing the length of the transport pathway, the hydraulic resistance of the vascular tissues should increase. It is not clear if trees only rely on passive transport mechanisms (no active loading of sugars) to move carbohydrates from shoots to roots. To answer this question,…

Manganese is a micronutrient essential for the function of several proteins including manganese superoxide dismutase (localized in the peroxisome and mitochondria) and the photosystem II reaction center (localized in the chloroplast). Mn is transported via NRAMP (Natural Resistance-Associated Macrophage…

Plants that can accumulate metals or metalloids in their living tissues to extremely high levels (hyperaccumulators) can be used to model metal uptake and biotic interactions and used for phytoremediation, among other uses. While the uses for hyperaccumulators are vast, until now a database with global…

Polar localized PIN FORMED (PIN) efflux carriers proteins organize directional auxin flow and accumulation. Most flowering plants have  another family of PIN proteins called Sister of PIN1 (SoPIN1), which Arabidopsis and members of the Brassicacea family do not have. The grass Brachypodium dystachion…

“Over 200 million humans are at risk of arsenic poisoning,” due to arsenic in groundwater and its uptake into crops. Our understanding of the transporters through which arsenic enters the plant, moves through the plant, and enters the seed has increased substantially in recent years, opening the…

Hormones are signaling molecules, and in most (but not all) cases part of their function is to convey information from one cell or tissue to another, sometimes from cell-to-cell and sometimes through vascular tissues. Park et al.  review our current state of understanding of transporters for diverse…

Polished white rice is a major food source for much of the world but is not a good source of the essential micronutrients iron and zinc. Like microbes, plants enhance their uptake of iron from the environment by synthesizing small “iron carrying” molecules called respectively siderophores or phytosiderophores…

Many nutrients move through the plant body via the phloem. The developing embryo, which depends on the maternal plant for its nutrients, is not directly (symplastically) connected to maternal tissues, so nutrients must be exported across membranes to reach the embryo. PHO1 was identified previously as…

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…

Kloth et al. probe aphid feeding behavior. The Plant Cell 2017  doi: 10.1105/tpc.16.00424 By Karen Kloth Background: Aphids are phloem-feeding insects. They penetrate plants with a piercing-sucking mouth. Once they reach a tube where the plant transports its sugar-rich phloem sap, they can take…

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…

Through insertional mutagenesis of rice, Cheng et al. identified a BTBN (Brac/Tramtrack/Broad complex and NPH3 domain)-encoding gene which they named WINDING 1 (WIN1), because the mutant phenotype (caused by ectopic expression in the shoot) causes the shoot to grow in a spiral. Ectopic expression of…

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…

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…

Cells have developed different mechanisms including control of ion and pH homeostasis to adapt to their constantly changing environment. Such adaption is accomplished by different ion transporters at the membranes. AtCHX17, AtCHX18 and AtCHX20 are members of the cation-H+ exchanger (CHX) family, which…

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…

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…

The MATE (multidrug and toxic compound extrusion) family is found in all three domains of life. Proteins in this family are secondary transporters, functioning as sodium or proton/organic cation antiporters. This family has diverse functions in plants, including vacuolar sequestration of alkaloids,…

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…

Nuclear accidents in recent years such as the Fukushima incident during the tsunami in 2011 revealed the detrimental effects of leaked radioactive cesium (Cs) in environmental soil and water. Due to Cs's chemical similarity with potassium, an essential macronutrient for plants, cesium is taken up by…

CAM (crassulacean acid metabolism) is the form of photosynthesis in which carbon assimilation occurs at night. CAM allows plants, especially those growing in arid regions, to avoid excessive water loss. With the long-term goal of eventually engineering this water-conserving trait into crop plants, Wai…

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.…

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…

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…

Plant hormones are made in one tissue and usually transported to act in another. One example of this is the transport of cytokinin.  In the root, the precursor trans-zeatin riboside (tZR) is synthesized, then xylem loaded and transported to the shoot. Once at a site of action like the leaf or shoot…

By Elide Formentin Rice (Oryza sativa), the primary source of calories for more than 2 billion people, is the most sensitive of all cereal crops to soil salinity, which affects more than 20% of irrigated arable land (FAO and ITPS, 2015). Rice paddies are mainly located at the delta of rivers, where…

Plants can emit up to 10% of the carbon they fix as volatile organic compounds (VOCs), which function in abiotic stress tolerance, pollinator attraction, signalling between plants, and defending against pathogens and herbivores. It has been an open question whether these small molecules pass directly…

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…

Plants undergo photosynthesis in leaves to produce carbohydrates sucrose and starch. The sucrose is transported to other parts of the plants via sugar transporters called SWEET proteins. In addition, certain plant pathogens activate SWEET genes to invade their host. As shown in this paper, during bacterial…

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…

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…

Nodules are specialized structures that form symbiotic, nitrogen-fixing associations with rhizobia on some plants including Medicago truncatula. Previous work has shown that auxin signalling is involved in nodule formation. Roy et al. extend this knowledge through the identification of a Medicago gene…

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…

Rice is a staple food for half of the world’s population, but it accumulates the toxic metalloid arsenic (As), which is present in soils and in plants in two forms, arsenate (AsV) and arsenite (AsIII). Chen et al. review the genetics and biochemistry of As uptake and sequestration into the rice grain,…

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;…

In C3 plants at ambient CO2 levels, Rubisco’s oxygenation reaction occurs about once for every three carboxylation reactions. One of the oxygenation products, 2-phosphoglycolate, is rapidly dephosphorylated to glycolate which is toxic and inhibitory to photosynthesis. Glycolate has to be removed from…

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 BRIEF by Gregory Bertoni [email protected] Proper localization of proteins in the plasma membrane is critical for proper functioning of plant cells, but the underlying mechanisms are poorly understood (Łangowski et al, 2016). This is especially true for transporter proteins that move necessary…

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…

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…

Which arose first during evolution- a metabolite molecule or a transporter that could move it across a membrane?  Jørgensen et al. studied transporters for glucosinolate defense molecules in Brassicales species.  Glucosinolates are derived from the broad class of cyanogenic glucosides, and glucosinolates…

Transfer cells (TCs) play critical roles in membrane transport of solutes at various sites within plants and between plants and their environment. This transport capacity is conferred by inward wall protuberances that extend into the cell lumen. These ingrowths function to enhance the area of surrounding…

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…

Like other organisms, plants have developed mechanisms to sense and respond to changes in the availability of nutrients. Nitrogen (N), being very essential for the growth and development of plants, must also be strongly monitored by plants. N sensing and signaling in plants are highly researched topics,…

Hydathodes are the sites of guttation, which is a process by which water and solutes are pushed out of leaves by the force of root pressure when the rate of transpiration is low (for example at night).  Hydathodes have numerous stomata-like pores and are located near vascular ends. Like stomata, hydathodes…

The New Phytologist Tansley Medal is awarded to an early career scientist for excellence in plant science. The essays submitted by each of the five finalists are published in the March 2017 of New Phytologist, and make good reading. We agree with the sentiments of the editors, “warmest congratulations…

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…

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,…

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…

Iron (Fe) is a frequently limiting nutrient for plant growth. Iron uptake requires that plants manipulate the extracellular environment through secretion of protons, chelators and other molecules. Curie and Mari review new studies on the importance of coumarin (phenolic compound) secretion in iron uptake,…

Saline soils are an ever growing problem, whether due to seawater incursions, for example in Bangladesh, or due to the rising water table in Australia. Salinity is harmful in three ways: non-specific osmotic effects, excess Na+, and excess Cl–. Of these, chloride has received the least attention. Li…

Phosphorus (P) is an important macronutrient for crop productivity.  In cereal crops like rice, about 60-85% of total plant P is allocated to grains and therefore removed from fields at harvest. Furthermore, the major form of P in the grains is phytate (C6H18O24P6), which cannot be digested by humans…

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…

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,…

Nitrogen (N), phosphorus (P), and potassium (K) are the three macronutrients required in highest amounts for plant growth. N is abundant in the atmosphere, therefore plentiful if we overlook the energetic costs of converting N2 to usable form. By contrast, K and P are present in limited amounts in the…

Cadmium (Cd) is among the most toxic heavy metal to humans. Contamination of Cd in soils poses a serious threat to both crop productivity and human health in many parts of the world. Understanding the molecular mechanisms of Cd transport process will help in developing plants for soil remediation and…

Soil saline-alkalization is a major abiotic stress to agriculture worldwide, causing considerable damage to crop growth and loss of crop productivity. In alkaline soil, iron availability to plants also becomes very limiting. This paper explores the physiological and molecular mechanisms of rice plant’s…

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…

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…

Biofortification is the nutritional enhancement (using conventional or genetic engineering approaches) of food with vitamins or micronutrients with the goal of improving the human diet. A set of new reviews in Current Opinion in Biotechnology summarizes progress towards biofortification of plants to…

The cytosol of most plant cells are connected by plasmodesmata, tiny channels that form bridges between adjoining cells (guard cells notably lack plasmodesmatal connections). Water, ions, small molecules, proteins and viruses can move through plasmodesmata. Upon wounding or infection, plasmodesmatal…

When villagers see the marauding hordes approaching, they secure their food sources. Similarly, when the cell-surface FLS2 receptor detects a bacterial pathogen, it (through its co-receptor BAK1) phosphorylates and stimulates the activity of a cell-surface sugar transporter (STP13), leading to the…

Nitrogen-fixing cyanobacteria such as Anabaena sp. PCC 7120 have the challenge of supporting nitrogenase, an enzyme that is highly sensitive to oxygen, and simultaneously photosynthesis, an oxygen-producing set of reactions. They accomplish this by segregating these reactions into two cells, heterocysts…

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…

IN BRIEF by Jennifer Mach [email protected] Plants can dispose of organs such as leaves and recycle the nutrients in these organs into new leaves, seeds, or storage organs. However, when separated from its photosystem proteins, chlorophyll can be phototoxic, absorbing light and producing high-energy…