The science of the stomata of plants: a continuously growing list of references, abstracts and illustrations, helping researchers to data on publications.
Virus-induced gene editing (VIGE) holds promise as a rapid and scalable approach for functional genomics in plants. Here, we apply a tobacco rattle virus (TRV)-based single-guide RNA (sgRNA) delivery system to target key regulators of stomatal development in Nicotiana benthamiana using transgenic Cas9-expressing lines. sgRNAs fused to a mobile RNA element and co-delivered with TRV enabled both somatic and heritable genome editing across orthologs of STOMAGEN, EPF2, YODA, and SPEECHLESS. Somatic editing frequencies reached up to 95%, and heritable tetra-allelic mutations were recovered in multiple target genes.
Mutants exhibited significant, gene-specific changes in stomatal density, with corresponding effects on leaf temperature indicative of altered evaporative cooling. Additionally, sgRNAs fused to an AmCyan reporter enabled visualization of virus-infected tissues, allowing stomatal phenotyping in edited M0 sectors.
This TRV-based platform facilitates functional assessment of genes influencing stomatal patterning and offers a powerful tool for dissecting gene function in a developmentally and physiologically relevant context.
Sessile plants rely on individual cells to perceive pathogens and coordinate defense. Guard cells (GCs), best known for regulating stomatal aperture, have poorly understood intrinsic immune roles.
Here, we integrate single-cell and spatial analyses of Arabidopsis thaliana leaves infected with diverse phytopathogens, combining live and fixed imaging of transgenic immune reporters with single cell transcriptomic data. Powdery mildew infection triggers strong salicylic acid (SA) biosynthesis and transport in pavement cells, spreading to neighboring uninfected cells. In contrast, GCs fail to activate SA biosynthesis or SA-responsive genes. These cell-type-specific immune programs distinguishing GC and pavement cells are conserved across infections by the hemibiotrophic fungus Colletotrichum higginsianum and the bacterial pathogen Pseudomonas syringae. Despite impaired SA signaling and response, GCs display rapid calcium influx and pronounced reactive oxygen species bursts, transmitting immune signals to adjacent pavement cells via the apoplast.
Notably, GCs are incompatible with adapted fungal pathogens and underwent hypersensitive cell death. Together, these findings uncover distinct immune programs among epidermal cell types, highlight GC-autonomous defense mechanisms, and provide a framework for understanding spatial immune coordination in plants.
Extreme environments test the limits of plant adaptation, from the searing heat of deserts to the frigid winters of the Arctic. Plants have evolved remarkable strategies to endure these harsh conditions while maintaining essential functions like photosynthesis and reproduction. Succulents in deserts store water for months, while cushion plants in the Arctic trap heat under strong winds, creating microclimates that sustain metabolic activity.
Short growing seasons, nutrient-poor soils, and unpredictable water availability push plants to develop intricate survival mechanisms. Mycorrhizal networks extend root reach, CAM photosynthesis reduces water loss, and cold-hardening proteins prevent freezing. These adaptations highlight how plant survival is a balance between environmental constraints and physiological efficiency, enabling life to thrive where few other organisms can.
How Do Plants Survive Desert Extreme Environments?
Desert plant adaptation focuses on conserving water and thriving under intense heat. Cacti use spines to reduce herbivory and shade stomata, lowering transpiration by up to 75%. Succulents like agaves store water and employ CAM photosynthesis, fixing CO2 at night to minimize daytime water loss.
Shallow, widespread roots capture flash flood water, while deeper mesquite roots tap aquifers up to 50 meters below. Waxy cuticles and sunken stomata slow evaporation, and ephemeral species complete their life cycles within weeks after rainfall. Resurrection plants tolerate near-total desiccation, reviving when moisture returns, demonstrating extreme physiological resilience.
What Are Arctic Plant Survival Adaptations?
Arctic plant survival relies on cold hardening, triggered by shortening days, which increases the levels of antifreeze proteins and unsaturated membrane lipids. Low growth forms, including cushions and mats, create microclimates that can be 10–20°C warmer than the surrounding air, allowing metabolic activity during brief summers.
Evergreens resorb 50–80% of nutrients before leaf drop, storing them in roots for rapid spring growth. Mycorrhizal associations extract phosphorus from thin soils, while graminoids produce multiple tillers during short summers. Heliotropic and parabolic flowers maximize heat for pollinators, ensuring reproductive success despite cold temperatures.
How Do Plant Adaptations Differ Between Deserts and Arctic?
Desert plants adapt to conserve water with reduced leaves, thick cuticles, and CAM photosynthesis, while Arctic plants survive freezing temperatures through supercooling mechanisms. Geophytes in deserts escape harsh periods underground, whereas Arctic perennials overwinter beneath insulating snow, resuming growth immediately when conditions improve.
Nutrient management differs: desert plants rely on rapid decomposition and quick cycling, whereas Arctic flora resorb nutrients before senescence to conserve limited resources. Photoperiod adjustments help Arctic plants exploit low-angle sunlight, while deserts rely on heat-shock proteins to withstand midday heat. Symbiotic relationships aid both, but physiological processes are tuned to their extreme environments.
Evolutionary Insights into Plant Survival Mechanisms
Selection pressures have driven convergent evolution in extreme environments, producing similar adaptations like cushion saxifrages and desert hummocks that optimize thermal regulation. Polyploidy enhances cold tolerance, while resurrection genes trace to ancient desiccation events in desert species. Climate change is pushing species’ ranges poleward, testing the limits of adaptation in both deserts and Arctic regions.
Genetic diversity and hybridization generate new tolerances, ensuring ecosystem resilience. Conserving these alleles in genetic banks safeguards against future environmental shifts. Understanding plant adaptation across extreme environments illuminates how evolutionary pressures shape survival tactics and maintain biodiversity under harsh conditions.
Mastering Plant Adaptation Across Extreme Environments
Extreme habitats—from deserts with minimal rainfall to Arctic regions with subzero temperatures—highlight the power of plant adaptation strategies. Plants have evolved mechanisms such as water storage, CAM photosynthesis, antifreeze proteins, low-growth forms, and nutrient resorption to thrive in conditions that challenge survival. These strategies maintain ecosystem function and ensure reproductive success despite environmental constraints.
By studying plant adaptation in these harsh regions, scientists can better understand resilience, informing conservation and agricultural practices. Genetic insights and symbiotic relationships demonstrate how evolution balances survival with environmental pressures, offering lessons for managing biodiversity under climate change. Knowledge of these adaptations underscores the intricate ways life persists at Earth’s extremes.
1. How do desert plants survive with so little water?
Desert plants survive through water storage in stems and leaves, reduced leaf surfaces, and CAM photosynthesis, which fixes CO2 at night to minimize water loss. Deep and wide root systems capture scarce rain, and some species complete their life cycle quickly after rainfall. Waxy cuticles and spines reduce evaporation, and resurrection plants can revive from near-total desiccation. These combined strategies allow plants to thrive in extremely arid environments.
2. How do Arctic plants avoid freezing during winter?
Arctic plants use cold-hardening to increase antifreeze proteins and unsaturated membrane lipids, preventing ice formation in cells. Low-growth forms like cushions create microclimates that trap heat, while snow acts as insulation. Evergreens store nutrients and maintain metabolic readiness under snow cover. Supercooling allows water to remain liquid below freezing, supporting survival during extreme cold.
3. Why do desert and Arctic plants have different nutrient strategies?
Desert plants rely on rapid decomposition and fast nutrient cycling due to infrequent rainfall. Arctic plants absorb nutrients before leaf drop to retain resources in nutrient-poor, slow-decomposing soils. These strategies maximize survival within their respective ecosystems. Both adaptations optimize growth and reproduction despite environmental constraints.
4. Can plants survive if extreme environments worsen due to climate change?
Plants face increasing stress from rising temperatures, shifting precipitation, and permafrost thaw. Genetic diversity and hybridization provide some resilience, enabling adaptation to changing conditions. Conservation of seeds and alleles in genetic banks helps protect against loss of unique adaptations. However, rapid environmental changes may outpace natural evolutionary processes, threatening vulnerable species.
National Key Laboratory of Crop Genetic Improvement, Ministry of Agriculture and Rural Affairs Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
Drought poses a significant threat to global rice production, and a comparative study between rice and wheat serves as an essential approach to unravel the mechanisms relating to drought tolerance. This study examined the differential responses of gas exchange, leaf hydraulic conductance, and leaf morpho-anatomical traits in Shanyou 63 (Oryza sativa) and Yannong 19 (Triticum aestivum).
Our findings revealed that rice photosynthesis was more sensitive to drought than wheat, primarily due to greater reductions in stomatal conductance (gs) and mesophyll conductance (gm). The larger reduction of gs in rice was related to a more substantial decrease in leaf hydraulic conductance, which was driven by more severe downsizing of leaf xylem conduits and the thickened mestome cell walls. The more severe depression of gm in rice under drought was associated with the decreased chloroplast surface area exposed to intercellular airspaces and cell wall porosity (φ/τ) as well as the thickened mesophyll cell walls (Tcw-mes). The thicker Tcw-mes and the decreased φ/τ may be related to the biosynthesis and deposition of cellulose and hemicellulose.
This study provides evidence that the regulation of cell wall components and the retention of leaf morphological and anatomical structures play a critical role in maintaining a high photosynthetic capacity under drought stress.
Rising concentrations of atmospheric CO2 (ca) increase plant photosynthesis (An) and reduce stomatal conductance (gs). This increases the intrinsic water-use efficiency (iWUE = An / gs), a major proxy of tree adaptation to climate change. However, whether an increase in iWUE leads to a concomitant increase in tree growth remains in dispute, prompting interest in theoretical links between iWUE and tree productivity.
Here using an optimality theory for kinetics of stomatal aperture, we establish an envelope delineating maximal relative increases in tree productivity that can be inferred/expected from relative increases in iWUE. The resulting expressions are used to interpret relations between iWUE (an observable proxy) and tree growth (the target variable), using available experimental data from manipulation experiments and tree-ring isotopes. While rising ca increases iWUE, proportional increases in tree growth are unlikely given ameliorating environmental (for example, rising atmospheric dryness) and anatomical/physiological (for example, tree height) influences.
Plants close their stomata to block pathogen entry, but how this defence is supported at the organelle level remains unclear. Our study reveals that immune signalling promotes MIRO1-dependent mitochondrial fusion in guard cells, supporting mitochondrial functional homeostasis that enables effective stomatal closure.
When clouds roll over a field or a greenhouse lamp dims, plant leaves have to choose fast. Keep pores open to grab carbon dioxide, or close them to save water. A new study has watched that choice unfold in real time and found that some familiar crops are surprisingly wasteful. What actually happens inside the leaf at that moment?
Scientists from the University of Twente and Wageningen University built aportable microscope that clips onto a living leaf and tracks dozens of stomata, the microscopic pores on its surface. In maize and chrysanthemum, they followed individual pores as light suddenly increased or decreased, mimicking the rapid flicker that happens all day in real crop canopies.
Tiny pores, big climate stakes
Stomata act like tiny valves. They let carbon dioxide in for photosynthesis and release water vapor. As the air warms and dries, and rainfall patterns shift, farmers in many regions already see crops demanding more irrigation water.
Light on a leaf rarely stays steady. Passing clouds, moving leaves and overlapping foliage constantly switch plants between shade and sun. Photosynthesis can adjust fairly quickly, but stomata lag behind. Research suggests this delay can cost crops about 10% to 40% of their potential daily carbon gain.
The new instrument sits on a tripod. A leaf is held gently between soft cushions so air and light still reach both sides. A ring of green light scans a patch of tissue smaller than a grain of rice and takes a stack of images at different depths every minute. Software combines the stack into a sharp surface view and automatically traces each pore as it opens and closes.
Because the leaf stays in its growth chamber or greenhouse, the thin layer of still air around it remains intact. That boundary layer is common outdoors and can shape stomatal behavior, especially on hot, dry afternoons when plants are already under stress.
In chrysanthemum, the system resolved full opening and closing patterns for roughly 78% of the stomata in view. In maize, it clearly tracked about 45%, enough to spot sharp contrasts between the two species.
Maize trains its pores, chrysanthemum wastes water
Under steady light, some maize stomata kept cycling between open and closed states. When light suddenly jumped to a saturating level, these “opening and closing” pores, if closed at that moment, snapped open faster than pores that had been closed and stable. That faster response boosted carbon dioxide uptake during bright spells.
When light dropped again, maize pores with larger openings tended to close quickly and without delay. In practical terms, that let the plant enjoy high gas exchange under strong light, then defend its water supply as soon as shade returned.
Chrysanthemum behaved differently. More than half of its stomata hesitated before closing or never fully closed after a decrease in light. Many pores stayed wider than needed for at least thirty minutes.
The team’s simulation suggests that removing a typical closing delay of about four minutes would save roughly 13% of the water lost in that half hour. Removing both the delay and the tendency to stop at a half closed state could cut water loss by around 40% for the average pore.
For growers who keep an eye on both irrigation bills and heat inside greenhouses, that kind of microscopic leak adds up. A variety whose stomata shut a little faster after shade could keep flowers healthy with less water and less energy for pumping and cooling.
From lab gadget to breeding tool
This microscope is not just a clever camera trick. It gives breeders a way to select crops based on how their pores actually move under realistic, fluctuating light. Instead of focusing only on how many stomata a leaf carries, they can look for lines where pores open quickly when light appears and close promptly when it fades.
Over time, tools like this could help deliver crop varieties that produce the same harvest with less water, or maintain yields when droughts and heat waves hit.
Drought poses a significant global challenge to agriculture, substantially reducing crop yields. Abscisic acid (ABA) plays a crucial role in response to drought stress. Nevertheless, the molecular mechanism underlying the ABA-mediated drought stress response in apple remains poorly understood. We identified a drought- and ABA-induced AP2/ERF transcription factor (TF), MhSHINE2-like, which positively regulates drought stress tolerance in apple. Biochemical analysis showed that MhSHINE2-like directly binds to the GAGA-rich element in the promoter of the ABA biosynthesis gene MhNCED3, promoting its transcription under drought stress.
Overexpression of MhNCED3 promotes ABA accumulation and enhances apple drought tolerance by regulating stomatal closure under drought stress. Further studies revealed that MhSHINE2-like physically interacts with 14-3-3 protein, MhGRF3, which also contributes positively to drought tolerance. Notably, MhSHINE2-like and MhGRF3 function cooperatively to modulate the expression of downstream genes, promoting ABA accumulation, and consequently enhancing drought tolerance in apple.
These findings reveal a regulatory network mediated by the combined effects of TFs and chaperone proteins, offering valuable genetic resources for the development of drought-tolerant apple cultivars.
Tempo-spatial intracellular Ca2+ changes/oscillations mainly in cytoplasm and nucleoplasm are the primary mechanisms for the encoding and transmission of upstream stimulating signals to corresponding downstream responses, and the cytosolic Ca2+ signals are involved in numerous biological processes. External Ca2+ influx mediated by Ca2+ channels in the plasma membrane (PM) and the Ca2+ release from intracellular Ca2+ stores, such as vacuoles and endoplasmic reticulum (ER), respectively contribute to the majority and minority of Ca2+ for the generation of cytosolic Ca2+ signals, and the dynamic changes of PM Ca2+ channel activity directly control the rhythms of external Ca2+ influx and the subsequent cytosolic Ca2+ oscillations. Thus, the PM Ca2+ channels are the core components for Ca2+ signal encoding, but remain to be addressed for decades.
Stomatal guard cell is an ideal plant cell model for deciphering Ca2+ signaling in plants, and more and more studies revealed that cyclic nucleotide-gated channels (CNGCs) play essential roles in Ca2+ signal encoding in guard cells. This minireview briefly summarizes the main recent advances in this field, highlights the core roles of CNGCs and underlying mechanism in guard cells, and discusses the possible remaining scientific questions and perspectives.
Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
The School of Molecular Biosciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
Abstract
Stomata of plant leaves open to enable CO2 entry for photosynthesis and close when CO2 in the leaf is elevated. CO2 is thought to promote stomatal closure in part by activating the SLAC1 anion channel at the guard cell plasma membrane. Carbonic anhydrases (CAs) contribute to this activation, but their contribution as distinct from CO2-H2CO3 catalysis remains controversial.
Here we show that the β-carbonic anhydrase CA4 binds selectively with the guard-cell anion channel SLAC1 to enhance channel current. The interaction is CO2-dependent, but binding is mediated by amino acids distal from the CO2-binding site of CA4 and is separable from carbonic-anhydrase activity. CA4 mutants impaired in channel binding eliminate the CO2-sensitivity of SLAC1 in vivo and slow stomatal kinetics with a commensurate loss in water use efficiency.
The findings demonstrate that CA4 contributes directly to the CO2-response mechanics regulating SLAC1 at near-ambient CO2 in guard cells and to stomatal kinetics in the plant.
PLANT STOMATA ENCYCLOPEDIA 
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