Actin marker lines in grapevine reveal a gatekeeper function of guard cells
14
Citation
70
Reference
10
Related Paper
Citation Trend
Keywords:
Plasmopara viticola
Stomatal movement is important for plants to exchange gas with environment. The regulation of stomatal movement allows optimizing photosynthesis and transpiration. Changes in vacuolar volume in guard cells are known to participate in this regulation. However, little has been known about the mechanism underlying the regulation of rapid changes in guard cell vacuolar volume. Here, we report that dynamic changes in the complex vacuolar membrane system play a role in the rapid changes of vacuolar volume in Vicia faba guard cells. The guard cells contained a great number of small vacuoles and various vacuolar membrane structures when stomata closed. The small vacuoles and complex membrane systems fused with each other or with the bigger vacuoles to generate large vacuoles during stomatal opening. Conversely, the large vacuoles split into smaller vacuoles and generated many complex membrane structures in the closing stomata. Vacuole fusion inhibitor, (2s,3s)-trans-epoxy-succinyl-l-leucylamido-3-methylbutane ethyl ester, inhibited stomatal opening significantly. Furthermore, an Arabidopsis (Arabidopsis thaliana) mutation of the SGR3 gene, which has a defect in vacuolar fusion, also led to retardation of stomatal opening. All these results suggest that the dynamic changes of the tonoplast are essential for enhancing stomatal movement.
Vicia
Cite
Citations (110)
Contents Summary 1018 I. Introduction 1018 II. Guard cell photosynthesis 1019 III. Guard cell central metabolism 1022 IV. Guard cell starch metabolism differs from that of mesophyll cells and plays a key role in stomatal movement 1025 V. Connectors between mesophyll and guard cells 1026 VI. Challenges and perspectives in understanding and modelling guard cell metabolism 1029 Acknowledgements 1030 References 1030 Summary Stomata are leaf epidermal structures consisting of two guard cells surrounding a pore. Changes in the aperture of this pore regulate plant water‐use efficiency, defined as gain of C by photosynthesis per leaf water transpired. Stomatal aperture is actively regulated by reversible changes in guard cell osmolyte content. Despite the fact that guard cells can photosynthesize on their own, the accumulation of mesophyll‐derived metabolites can seemingly act as signals which contribute to the regulation of stomatal movement. It has been shown that malate can act as a signalling molecule and a counter‐ion of potassium, a well‐established osmolyte that accumulates in the vacuole of guard cells during stomatal opening. By contrast, their efflux from guard cells is an important mechanism during stomatal closure. It has been hypothesized that the breakdown of starch, sucrose and lipids is an important mechanism during stomatal opening, which may be related to ATP production through glycolysis and mitochondrial metabolism, and/or accumulation of osmolytes such as sugars and malate. However, experimental evidence supporting this theory is lacking. Here we highlight the particularities of guard cell metabolism and discuss this in the context of the guard cells themselves and their interaction with the mesophyll cells.
Osmolyte
Cite
Citations (85)
Plasmopara viticola
Proteome
Cite
Citations (23)
Stomata, functionally specialized small pores on the surfaces of leaves, regulate the flow of gases in and out of plants. The pore is opened by an increase in osmotic pressure in the guard cells, resulting in the uptake of water. The subsequent increase in cell volume inflates the guard cell and culminates with the opening of the pore. Although guard cells can be regarded as one of the most thoroughly investigated cell types, our knowledge of the signalling pathways which regulate guard cell function remains fragmented. Recent research in guard cells has led to several new hypotheses, however, it is still a matter of debate as to whether guard cells function autonomously or are subject to regulation by their neighbouring mesophyll cells. This review synthesizes what is known about the mechanisms and genes critical for modulating stomatal movement. Recent progress on the regulation of guard cell function is reviewed here including the involvement of environmental signals such as light, the concentration of atmospheric CO2 and endogenous plant hormones. In addition we re-evaluate the important role of organic acids such as malate and fumarate play in guard cell metabolism in this process.
Guard (computer science)
Plant cell
Cell type
Cite
Citations (110)
Oxathiapiprolin is a novel fungicide and the first of the piperidinyl-thiazole-isoxazoline class to be discovered. This fungicide has been reported to have high activity against Plasmopara viticola, the grapevine downy mildew agent, and other plant-pathogenic oomycetes. In this study, the baseline sensitivity of Italian P. viticola populations towards oxathiapiprolin was established on 29 samples collected in 10 different viticultural areas. Two insensitive strains were characterized for their mechanism of resistance.Oxathiapiprolin exhibited substantial inhibitory activity against 27 of the 29 populations tested, with EC50 values ranging from a minimum of under 4 × 10-5 mg L-1 to over 4 × 10-1 mg L-1 , with an average value of 3.2 × 10-2 mg L-1 . Two stable suspected oxathiapiprolin-resistant mutants were isolated from population exhibiting reduced sensitivity, and sequenced for the oxathiapiprolin target gene PvORP1. The comparison with wild-type isolates revealed that the resistant isolates possessed a heterozygous mutation causing the amino acid substitution N837I, recently reported in the literature.The results obtained indicate a risk for Italian P. viticola populations to develop resistance to oxathiapiprolin in association with the N837I mutation at PvORP1. Anti-resistance strategies should be carefully implemented and the sensitivity levels to this molecule should be monitored accurately in future to preserve its effectiveness. © 2022 Society of Chemical Industry.
Plasmopara viticola
EC50
Cite
Citations (9)
Summary Inducible plant defences against pathogens are stimulated by infections and comprise several classes of pathogenesis‐related (PR) proteins. Endo‐β‐1,3‐glucanases (EGases) belong to the PR‐2 class and their expression is induced by many pathogenic fungi and oomycetes, suggesting that EGases play a role in the hydrolysis of pathogen cell walls. However, reports of a direct effect of EGases on cell walls of plant pathogens are scarce. Here, we characterized three EGases from Vitis vinifera whose expression is induced during infection by Plasmopara viticola , the causal agent of downy mildew. Recombinant proteins were expressed in Escherichia coli . The enzymatic characteristics of these three enzymes were measured in vitro and in planta . A functional assay performed in vitro on germinated P. viticola spores revealed a strong anti‐ P. viticola activity for EGase3, which strikingly was that with the lowest in vitro catalytic efficiency. To our knowledge, this work shows, for the first time, the direct effect against downy mildew of EGases of the PR‐2 family from Vitis .
Plasmopara viticola
Glucanase
Oomycete
Cite
Citations (34)
The downy mildew(Plasmopara viticola) in grapevines is a world fungal disease with its badly high effects on the yield and quality of grape.Especially for the rainy climate in recent years,throughout the main viticultural regions it was more epidemic and affected badly.Therefore,the pathogenetic conditions,symptoms,cycles of infection of Plasmopara viticola together with the therapies were presented in detail,in order to work for our production.
Plasmopara viticola
Cite
Citations (0)
Summary Stomata can be regarded as hydraulically driven valves in the leaf surface, which open to allow CO 2 uptake and close to prevent excessive loss of water. Movement of these ‘Watergates’ is regulated by environmental conditions, such as light, CO 2 and humidity. Guard cells can sense environmental conditions and function as motor cells within the stomatal complex. Stomatal movement results from the transport of K + salts across the guard cell membranes. In this review, we discuss the biophysical principles and mechanisms of stomatal movement and relate these to ion transport at the plasma membrane and vacuolar membrane. Studies with isolated guard cells, combined with recordings on single guard cells in intact plants, revealed that light stimulates stomatal opening via blue light‐specific and photosynthetic‐active radiation‐dependent pathways. In addition, guard cells sense changes in air humidity and the water status of distant tissues via the stress hormone abscisic acid (ABA). Guard cells thus provide an excellent system to study cross‐talk, as multiple signaling pathways induce both short‐ and long‐term responses in these sensory cells. Contents Summary 665 I. Introduction 665 II. The hydrodynamic valve 666 III. Regulation of ion transport in guard cells 678 IV. Interaction between guard cell signaling pathways 682 V. Outlook 684 Acknowledgements 685 References 685
Cite
Citations (518)
Cite
Citations (45)
Experimental results are presented which show that abscisic acid (ABA) causes stomatal closure only if the stomatal complex is adjacent to live epidermal cells. It is further shown that ABA acts by affecting solute fluxes into and out of epidermal and guard cells. Live epidermal cells function as recipients for solutes and thereby assist their movement out of the guard cells. ABA-mediated solute leakage from guard cells alone does not suffice to cause stomatal closure within one hour.
Cite
Citations (27)