scholarly journals Element content and expression of genes of interest in guard cells are connected to spatiotemporal variations in stomatal conductance

2019 ◽  
Vol 43 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Maxime Durand ◽  
David Cohen ◽  
Nathalie Aubry ◽  
Cyril Buré ◽  
Ivana Tomášková ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Guard Cells ◽  
Element Content ◽  
Spatiotemporal Variations ◽  
Expression Of Genes

The transcription factor ZmNAC49 reduces stomatal density and improves drought tolerance in maize

2020 ◽  
Author(s):  
Yang Xiang ◽  
Xiujuan Sun ◽  
Xiangli Bian ◽  
Tianhui Wei ◽  
Tong Han ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Stomatal Conductance ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Transcriptional Activation ◽  
Stomatal Density ◽  
Stomatal Development ◽  
Expression Of Genes ◽  
Growth Development

Abstract Drought stress severely limits the growth, development, and productivity of crops, and therefore understanding the mechanisms by which plants respond to drought is crucial. In this study, we cloned a maize NAC transcription factor, ZmNAC49, and identified its function in response to drought stress. We found that ZmNAC49 is localized in the nucleus and has transcriptional activation activity. ZmNAC49 expression is rapidly and strongly induced by drought stress, and overexpression enhances stress tolerance in maize. Overexpression also significant decreases the transpiration rate, stomatal conductance, and stomatal density in maize. Detailed study showed that ZmNAC49 overexpression affects the expression of genes related to stomatal development, namely ZmTMM, ZmSDD1, ZmMUTE, and ZmFAMA. In addition, we found that ZmNAC49 can directly bind to the promoter of ZmMUTE and suppress its expression. Taken together, our results show that the transcription factor ZmNAC49 represses ZmMUTE expression, reduces stomatal density, and thereby enhances drought tolerance in maize.

Genetic analysis of stomatal conductance in upland cotton (Gossypium hirsutum L.) under contrasting temperature regimes

2005 ◽  
Vol 143 (2-3) ◽  
pp. 161-168 ◽  
Author(s):  
H. U. RAHMAN
Keyword(s):  
Heat Stress ◽  
Stomatal Conductance ◽  
Temperature Regime ◽  
Upland Cotton ◽  
Selection Efficiency ◽  
Gossypium Hirsutum L ◽  
The Third ◽  
Expression Of Genes ◽  
Temperature Regimes ◽  
Genetically Determined

Stomatal conductance plays an important role in the heat avoidance mechanism of crop plants. Stomatal conductance in cotton is genetically determined and has been shown to be associated with heat resistance and higher yields. Experiments were carried out with six generations (parental, F1, F2 and back crosses) of three upland cotton crosses under heat-stressed and non-stressed greenhouse and field regimes, to understand the inheritance pattern of stomatal conductance as affected by contrasting temperature regimes. The results revealed significant variation for stomatal conductance due to generations and generation×temperature regime interaction in the three crosses. In general, heat stress reduced stomatal conductance and available genetic variability. Temperature regimes exerted a significant effect on the expression of the genes responsible for stomatal conductance. High temperature or heat stress favoured the expression of genes having additive effects, while absence of heat stress favoured those having dominant effects in two of the three crosses evaluated. The third cross showed the opposite reaction. The results suggest that genes controlling stomatal conductance in the parents of the first two crosses (MNH-552, HR109-RT, CIM-448, CRIS-19) were different from those controlling stomatal conductance in FH-900 and N-Karishma, the parents of the third cross. The selection efficiency of stomatal conductance in segregating populations was likely to be affected by the complexity of its inheritance, environmental dependency, and presence of substantial non-allelic and genotype×temperature regime interactions.

How stomata resolve the dilemma of opposing priorities

1976 ◽  
Vol 273 (927) ◽  
pp. 551-560 ◽  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Loss ◽  
Stomatal Closure ◽  
Guard Cells ◽  
Xanthium Strumarium ◽  
Solute Content ◽  
Stomatal Responses ◽  
Saturation Kinetics ◽  
Use Efficiency

Satisfaction of a leaf’s need for CO 2 requires an intensive gas exchange between mesophyll and atmosphere; prevention of excessive water loss demands that gas exchange be kept low. Stomata open when a low CO 2 concentration in the guard cells triggers ( a ) uptake of K + in exchange of H + , ( b ) production of organic acids, and ( c ) import of Cl - . ‘Hydropassive’ stomatal closure (i.e. turgor loss without reduction of the solute content of the guard cell) appears insufficient to protect the plant from desiccation. An additional ‘hydroactive’ solute loss is necessary; it is brought about by (+)-abscisic acid (ABA) acting as feedback messenger between mesophyll and epidermis. Stomatal closure not only curbs water loss but improves water-use efficiency because transpiration is proportional to stomatal conductance (at constant temperature). In contrast, assimilation, following saturation kinetics with respect to intercellular CO 2 , is relatively insensitive to changes in stomatal conductance (as long as stomata are wide open). In Xanthium strumarium , the amplitude of stomatal responses to ABA depends on the concentration of CO 2 in the guard cells; the opposite statement is also true. These interactions cause stomata to behave like ‘adjustable control systems’ capable of giving priority either to CO 2 assimilation or to water husbandry.

scholarly journals TuMV triggers stomatal closure but reduces drought tolerance in Arabidopsis

2020 ◽  
Author(s):  
Carlos Augusto Manacorda ◽  
Gustavo Gudesblat ◽  
Moira Sutka ◽  
Sergio Alemano ◽  
Franco Peluso ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Drought Tolerance ◽  
Time Course ◽  
Stomatal Closure ◽  
Guard Cells ◽  
Change Scenario ◽  
Daily Water ◽  
Responsive Gene ◽  
Non Destructive

i)SummaryIn this work the effects of TuMV infection on stomatal closure and water balance were studied in Arabidopsis. Thermal imaging analyses showed that TuMV-infected plants had consistently higher foliar temperature than mock treated controls. Non-destructive time-course experiments revealed that this differential phenotype was stable during both daytime and nighttime. This effect was due to reduced gas exchange in TuMV-infected plants, as observed through stomatal conductance and stomatal aperture assays in systemic leaves. Measurements of daily water consumption and initial dehydration rate further proved that TuMV infection reduced water loss. Salicylic acid (SA) and abscisic acid (ABA) contents were increased in TuMV-infected plants. In addition, the expression of ABI2, involved in ABA signaling, was enhanced, and ABCG40 (required for ABA transport into guard cells) was highly induced upon TuMV infection. Hypermorfic abi2-1 mutant plants, but no other ABA or SA biosynthetic, signaling or degradation mutants tested abolished both stomatal closure and low stomatal conductance phenotypes caused by TuMV. Therefore, not overall ABA levels, but localized differences in ABA import and perception in guard cells, are likely to be responsible for stomatal closure observed under TuMV infection. Plants simultaneously subjected to drought and viral stresses showed higher mortality rates than their mock-inoculated drought stressed counterparts, consistent with down-regulation of drought-responsive gene RD29A, both in short and long day conditions. Our findings indicate that in spite of stomatal closure triggered by TuMV, additional phenomena cause compromised drought tolerance of TuMV-infected Arabidopsis plants.ii)Significance statementCharacterization of the physiological responses controlling plant water management under combined stresses and the genes behind them is important in the current climate change scenario, which poses multifaceted challenges to crops. We found that TuMV infection induced ABA and SA accumulation and stomatal closure in Arabidopsis, alongside with overexpression of ABCG40 (the transporter of ABA to guard cells), whereas the dehydration-responsive gene RD29A was downregulated, concomitantly with increased plant susceptibility to drought stress under infection.

Silicon deposition on guard cells increases stomatal sensitivity as mediated by K + efflux and consequently reduces stomatal conductance

2020 ◽  
Author(s):  
Rebecca K. Vandegeer ◽  
Chenchen Zhao ◽  
Ximena Cibils‐Stewart ◽  
Richard Wuhrer ◽  
Casey R. Hall ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Guard Cells ◽  
Silicon Deposition ◽  
Stomatal Sensitivity

scholarly journals The role of strigolactones in regulation of stomatal conductance and plant-pathogen interactions inArabidopsis thaliana

2019 ◽  
Author(s):  
Maria Kalliola ◽  
Liina Jakobson ◽  
Pär Davidsson ◽  
Ville Pennanen ◽  
Cezary Waszczak ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stomatal Conductance ◽  
Pseudomonas Syringae ◽  
Guard Cell ◽  
Stomatal Closure ◽  
Cell Signalling ◽  
Guard Cells ◽  
Signalling Pathway ◽  
Ozone Sensitivity

AbstractStrigolactones are a group of phytohormones that control shoot branching inArabidopsis thaliana. However, in recent years they have been shown to affect many other plant processes. We previously showed that the strigolactone perception mutantmore axillary branches 2 (max2)has increased susceptibility to plant pathogenic bacteria as a result of more open stomata as well as alterations in hormonal signalling. Here we show that both, strigolactone biosynthesis- (max3andmax4), and perception mutants (max2anddwarf14) are significantly more sensitive toPseudomonas syringaeDC3000. Moreover, in response toP. syringaeinfection, high levels of SA accumulated inmax2and this mutant was ozone sensitive. To search for the mechanisms that could explain pathogen- and ozone sensitivity we performed gene expression analysis and several different assays that explore the function of guard cells and regulation of guard cell signalling.Treatments with GR24 (a strigolactone analogue) resulted in very modest changes in defence-related gene expression. In contrast, guard cell function was clearly impaired inmax2and depending on the assay used, also inmax3, max4andd14mutants. Moreover, stomatal responses to stimuli that cause stomatal closure in wild-type plants (darkness, high CO2and ABA) were analysed in the strigolactone mutants. In darkness both strigolactone biosynthesis and perception mutants showed reduced stomatal closure, whereas the response to high CO2was impaired only inmax2andd14. The response to ABA was not impaired in any of the mutants. To position the role of MAX2 in the guard cell signalling network,max2was crossed with mutants defective in ABA biosynthesis (aba2), in guard cell ABA signalling (ost1) and a scaffold protein required for proper ion channel activity (ghr1). The stomatal conductance of double mutants was consistently higher than the corresponding single mutants, suggesting that MAX2 acts in a signalling pathway that functions in parallel to the well characterized guard cell ABA signalling pathway. We propose that the impaired defence responses ofmax2is related to more open stomata that allows increased entry of bacteria or air pollutants like ozone. Furthermore, as MAX2 appears to act in a specific branch of guard cell signalling (related to CO2signalling), this protein could be one of the elusive components that allow guard cells to distinguish between different environmental conditions.

A Scanning Electron Microscope Study of Isolated Guard Cells

1973 ◽  
Vol 31 ◽  
pp. 454-455 ◽  
Author(s):  
P. Dayanandan ◽  
P. B. Kaufman
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Three Dimensional ◽  
Guard Cells ◽  
Scanning Electron Microscope Study ◽  
Psilotum Nudum ◽  
Subsidiary Cells ◽  
Welwitschia Mirabilis ◽  
Cycas Revoluta ◽  
Scanning Electron

A three dimensional appreciation of the guard cell morphology coupled with ultrastjuctural studies should lead to a better understanding of their still obscure dynamics of movement. We have found the SEM of great value not only in studies of the surface details of stomata but also in resolving the structures and relationships that exist between the guard and subsidiary cells. We now report the isolation and SEM studies of guard cells from nine genera of plants.Guard cells were isolated from the following plants: Psilotum nudum, four species of Equisetum, Cycas revoluta, Ceratozamia sp., Pinus sylvestris, Ephedra cochuma, Welwitschia mirabilis, Euphorbia tirucalli and Allium cepa.

609: Effects of Sirna and Phytoestrogen Treatments on the Expression of Genes Regulated through the Androgen Receptor of Lncap Prostate Cancer Cells

2004 ◽  
Vol 171 (4S) ◽  
pp. 162-162
Author(s):  
Paul Thelen ◽  
Michal Grzmil ◽  
Iris E. Eder ◽  
Barbara Spengler ◽  
Peter Burfeind ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Prostate Cancer Cells ◽  
Expression Of Genes
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