scholarly journals Atmospheric H2S exposure does not affect stomatal aperture in maize

Planta ◽  
2020 ◽  
Vol 252 (4) ◽  
Author(s):  
Ties Ausma ◽  
Jeffrey Mulder ◽  
Thomas R. Polman ◽  
Casper J. van der Kooi ◽  
Luit J. De Kok
Keyword(s):  
Hydrogen Sulfide ◽  
Transpiration Rate ◽  
Stomatal Density ◽  
Stomatal Closure ◽  
Stomatal Resistance ◽  
Stomatal Aperture ◽  
Sulfur Source ◽  
Growth Reduction ◽  
Signal Molecule ◽  
Lower Biomass

Abstract Main conclusion Stomatal aperture in maize is not affected by exposure to a subtoxic concentration of atmospheric H2S. At least in maize, H2S, thus, is not a gaseous signal molecule that controls stomatal aperture. Abstract Sulfur is an indispensable element for the physiological functioning of plants with hydrogen sulfide (H2S) potentially acting as gasotransmitter in the regulation of stomatal aperture. It is often assumed that H2S is metabolized into cysteine to stimulate stomatal closure. To study the significance of H2S for the regulation of stomatal closure, maize was exposed to a subtoxic atmospheric H2S level in the presence or absence of a sulfate supply to the root. Similar to other plants, maize could use H2S as a sulfur source for growth. Whereas sulfate-deprived plants had a lower biomass than sulfate-sufficient plants, exposure to H2S alleviated this growth reduction. Shoot sulfate, glutathione, and cysteine levels were significantly higher in H2S-fumigated plants compared to non-fumigated plants. Nevertheless, this was not associated with changes in the leaf area, stomatal density, stomatal resistance, and transpiration rate of plants, meaning that H2S exposure did not affect the transpiration rate per stoma. Hence, it did not affect stomatal aperture, indicating that, at least in maize, H2S is not a gaseous signal molecule controlling this aperture.

scholarly journals Complexity of ABA signaling for stomatal development and aperture regulation

2018 ◽  
Author(s):  
Pirko Jalakas ◽  
Ebe Merilo ◽  
Hannes Kollist ◽  
Mikael Brosché
Keyword(s):  
Stomatal Conductance ◽  
Stomatal Density ◽  
Stomatal Closure ◽  
Critical Role ◽  
Water Flux ◽  
Stomatal Aperture ◽  
Stomatal Development ◽  
Triple Mutant ◽  
Aperture Width ◽  
Dependent Pathway

AbstractStomata, small pores on the surfaces of leaves formed by a pair of guard cells, adapt rapidly to changes in the environment by adjusting the aperture width. As a long term response, the number of stomata is regulated during stomatal development. The hormone abscisic acid (ABA) regulates both processes. In ABA mediated guard cell signaling the protein kinase OPEN STOMATA1 (OST1) has a central role, as stomatal closure in the ost1 mutant is impaired in response to ABA and to different environmental stimuli. We aimed to dissect the contribution of different ABA-related regulatory mechanisms in determining stomatal conductance, a combination of stomatal density and aperture width, and crossed the ost1 mutant with mutants that either decreased (aba3) or increased (cyp707a1/a3) the concentration of ABA in plants. The double mutant ost1 aba3 had higher stomatal conductance than either parent due to a combination of increased stomatal aperture width and higher stomatal density. In the triple mutant ost1 cyp707a1/a3 stomatal conductance was significantly lower compared to ost1-3 due to lower stomatal density. Further characterization of the single, double and triple mutants showed that responses to treatments that lead to stomatal closure were impaired in ost1 as well as ost1 aba3 and ost1 cyp707a1/a3 mutants, supporting a critical role for OST1 in stomatal aperture regulation. Based on our results, we suggest that there are two signaling pathways to regulate water flux from leaves i.e. stomatal conductance: an ABA-dependent pathway that determines stomatal density independent of OST1; and an OST1-dependent pathway that regulates rapid changes in stomatal aperture.

scholarly journals Stomatal behavior and components of the antioxidative system in coffee plants under water stress

2011 ◽  
Vol 68 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Sidnei Deuner ◽  
José Donizeti Alves ◽  
Ilisandra Zanandrea ◽  
Patrícia de Fátima Pereira Goulart ◽  
Neidiquele Maria Silveira ◽  
...  
Keyword(s):  
Water Stress ◽  
Transpiration Rate ◽  
Vapor Pressure Deficit ◽  
Stomatal Closure ◽  
Field Capacity ◽  
Stomatal Resistance ◽  
Water Restriction ◽  
Coffee Plants ◽  
Hydrogen Peroxide Formation ◽  
In The Beginning

Coffee (Coffea arabica) plants show a positive relationship between stomatal closure and formation and accumulation of H2O2. However, for coffee plants under water restriction such relationship has never been studied. The objective of the present study was evaluate the stomatal movement and the antioxidant capacity of coffee seedlings under different water regimes. Eight months old coffee seedlings of cv. Catuaí IAC 99 were submitted to field capacity, gradual and total suspension of irrigation during a period of 21 days. Evaluations of leaf water potential (Ψw) were performed in the beginning of the morning, and stomatal resistance, transpiration rate and vapor pressure deficit were determined at 10 am and 5 pm. All biochemical and enzymatic determinations were performed in leaves collected at 5 pm. Evaluations and samplings were performed at three days intervals. There was no variation in Ψw during the evaluated period for plants in field capacity. However, an expressive decrease of Ψw following day 12, reaching values near -2.5 MPa at the end of the experiment was observed for plants submitted to gradual suspension of irrigation. For plants submitted to total suspension of irrigation, Ψw decreases after the sixth day, reaching -2.5 MPa at day 15. The decay of Ψw in plants submitted to gradual and total suspension of irrigation reflected in increased stomatal resistance and in a decreased transpiration rate leading to an increase in hydrogen peroxide formation and, on final stages, increase in lipid peroxidation. As a conclusion, an increase in the activity of antioxidant enzymes as well as in the levels of ascorbate and dehydroascorbate was observed, which act in the detoxification of free radicals formed as result of the water stress.

Transpiration and leaf water potentials of wheat in relation to changing soil water potential

1977 ◽  
Vol 28 (3) ◽  
pp. 355 ◽  
Author(s):  
KA Seaton ◽  
JJ Landsberg ◽  
RH Sedgley
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Transpiration Rate ◽  
Water Conservation ◽  
Root Zone ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Stomatal Resistance ◽  
Leaf Water ◽  
Water Potentials

Changes in the transpiration rate of wheat in drying soils were followed in experiments in which plants were grown in two small weighable lysimeters in a glasshouse. Hourly measurements of soil water potential (Ψs) were made at three depths in each lysimeter. The water potential of flag leaves was measured with a pressure chamber, and stomatal resistance with a pressure drop porometer. Data on root densities and distribution were also obtained. Transpiration rates fell below estimated potential levels when the average value of Ψs in the root zone was reduced to –1 to –5 bars, depending on soil storage, root distribution and potential transpiration rate. From this point Ψs fell rapidly in the surface layers, more slowly at depth. It was found that accurate calculations of daily water uptake could be made from changes in soil water content. The minimum value of leaf water potential (�1 )attained each day declined progressively through the drying cycle, but there was evidence that stomatal resistance (rs) is not uniquely related to Ψ1; initial stomatal closure occurred at Ψ1, values which decreased from –11 to –25 bars as drying progressed. This adaptive mechanism is related to changes in osmotic potential of the leaves. Whole plant resistances (Rp), derived from leaf water potentials and fluxes through individual stems, increased as stem populations increased. In the high population lysimeter Rp decreased from 300 to 100 bar sec mm-3 as canopy transpiration rates increased from 1.5 to 4.5 x 10-4 mm sec-1. In the low population lysimeter Rp decreased from 70 to 30 bar sec mm-3 as transpiration increased from about 2.2 to 4.5 x 10-4 mm sec-1. The higher resistances appear to confer significant advantages in terms of water conservation and adaptation to drought.

scholarly journals Is nitric oxide a critical key factor in ABA-induced stomatal closure?

2019 ◽  
Vol 71 (1) ◽  
pp. 399-410 ◽  
Author(s):  
Uulke Van Meeteren ◽  
Elias Kaiser ◽  
Priscila Malcolm Matamoros ◽  
Julian C Verdonk ◽  
Sasan Aliniaeifard
Keyword(s):  
Nitric Oxide ◽  
Stomatal Closure ◽  
Co2 Concentration ◽  
Stomatal Resistance ◽  
Stomatal Aperture ◽  
No Donor ◽  
Leaf Discs ◽  
Key Factor ◽  
Intact Leaves

Abstract The role of nitric oxide (NO) in abscisic acid (ABA)-induced stomatal closure is a matter of debate. We conducted experiments in Vicia faba leaves using NO gas and sodium nitroprusside (SNP), a NO-donor compound, and compared their effects to those of ABA. In epidermal strips, stomatal closure was induced by ABA but not by NO, casting doubt on the role of NO in ABA-mediated stomatal closure. Leaf discs and intact leaves showed a dual dose response to NO: stomatal aperture widened at low dosage and narrowed at high dosage. Overcoming stomatal resistance by means of high CO2 concentration ([CO2]) restored photosynthesis in ABA-treated leaf discs but not in those exposed to NO. NO inhibited photosynthesis immediately, causing an instantaneous increase in intercellular [CO2] (Ci), followed by stomatal closure. However, lowering Ci by using low ambient [CO2] showed that it was not the main factor in NO-induced stomatal closure. In intact leaves, the rate of stomatal closure in response to NO was about one order of magnitude less than after ABA application. Because of the different kinetics of photosynthesis and stomatal closure that were observed, we conclude that NO is not likely to be the key factor in ABA-induced rapid stomatal closure, but that it fine-tunes stomatal aperture via different pathways.

Hydrogen sulfide: a multi-tasking signal molecule in the regulation of oxidative stress responses

2020 ◽  
Vol 71 (10) ◽  
pp. 2862-2869 ◽  
Author(s):  
Tao Chen ◽  
Mimi Tian ◽  
Yi Han
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Sulfide ◽  
Stress Responses ◽  
Stomatal Closure ◽  
Plant Stress ◽  
Signal Molecule ◽  
Environmental Threats ◽  
Enhanced Production ◽  
Response Network ◽  
Plant Stress Responses

Abstract Accumulating evidence suggests that hydrogen sulfide (H2S) is an important signaling molecule in plant environmental interactions. The consensus view amongst plant scientists is that environmental stress leads to enhanced production and accumulation of reactive oxygen species (ROS). H2S interacts with the ROS-mediated oxidative stress response network at multiple levels, including the regulation of ROS-processing systems by transcriptional or post-translational modifications. H2S–ROS crosstalk also involves other interacting factors, including nitric oxide, and can affect key cellular processes like autophagy. While H2S often functions to prevent ROS accumulation, it can also act synergistically with ROS signals in processes such as stomatal closure. In this review, we summarize the mechanisms of H2S action and the multifaceted roles of this molecule in plant stress responses. Emphasis is placed on the interactions between H2S, ROS, and the redox signaling network that is crucial for plant defense against environmental threats.

Nitric oxide and hydrogen sulfide in plants: which comes first?

2019 ◽  
Vol 70 (17) ◽  
pp. 4391-4404 ◽  
Author(s):  
Francisco J Corpas ◽  
Salvador González-Gordo ◽  
Amanda Cañas ◽  
José M Palma
Keyword(s):  
Nitric Oxide ◽  
Hydrogen Sulfide ◽  
Environmental Conditions ◽  
Stomatal Closure ◽  
Experimental Conditions ◽  
Signal Molecule ◽  
Diverse Range ◽  
Range Of Functions ◽  
Adverse Environmental Conditions ◽  
Biochemical Analyses

Abstract Nitric oxide (NO) is a signal molecule regarded as being involved in myriad functions in plants under physiological, pathogenic, and adverse environmental conditions. Hydrogen sulfide (H2S) has also recently been recognized as a new gasotransmitter with a diverse range of functions similar to those of NO. Depending on their respective concentrations, both these molecules act synergistically or antagonistically as signals or damage promoters in plants. Nevertheless, available evidence shows that the complex biological connections between NO and H2S involve multiple pathways and depend on the plant organ and species, as well as on experimental conditions. Cysteine-based redox switches are prone to reversible modification; proteomic and biochemical analyses have demonstrated that certain target proteins undergo post-translational modifications such as S-nitrosation, caused by NO, and persulfidation, caused by H2S, both of which affect functionality. This review provides a comprehensive update on NO and H2S in physiological processes (seed germination, root development, stomatal movement, leaf senescence, and fruit ripening) and under adverse environmental conditions. Existing data suggest that H2S acts upstream or downstream of the NO signaling cascade, depending on processes such as stomatal closure or in response to abiotic stress, respectively.

scholarly journals Arabidopsis MADS-box factor AGL16 negatively regulates drought resistance via stomatal density and stomatal movement

2020 ◽  
Vol 71 (19) ◽  
pp. 6092-6106 ◽  
Author(s):  
Ping-Xia Zhao ◽  
Zi-Qing Miao ◽  
Jing Zhang ◽  
Si-Yan Chen ◽  
Qian-Qian Liu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Molecular Mechanisms ◽  
Stomatal Density ◽  
Stomatal Closure ◽  
Negative Regulator ◽  
Stomatal Development ◽  
Mads Box ◽  
Mobility Shift ◽  
Aba Metabolism

Abstract Drought is one of the most important environmental factors limiting plant growth and productivity. The molecular mechanisms underlying plant drought resistance are complex and not yet fully understood. Here, we show that the Arabidopsis MADS-box transcription factor AGL16 acts as a negative regulator in drought resistance by regulating stomatal density and movement. Loss-of-AGL16 mutants were more resistant to drought stress and had higher relative water content, which was attributed to lower leaf stomatal density and more sensitive stomatal closure due to higher leaf ABA levels compared with the wild type. AGL16-overexpressing lines displayed the opposite phenotypes. AGL16 is preferentially expressed in guard cells and down-regulated in response to drought stress. The expression of CYP707A3 and AAO3 in ABA metabolism and SDD1 in stomatal development was altered in agl16 and overexpression lines, making them potential targets of AGL16. Using chromatin immunoprecipitation, transient transactivation, yeast one-hybrid, and electrophoretic mobility shift assays, we demonstrated that AGL16 was able to bind the CArG motifs in the promoters of the CYP707A3, AAO3, and SDD1 and regulate their transcription, leading to altered leaf stomatal density and ABA levels. Taking our findings together, AGL16 acts as a negative regulator of drought resistance by modulating leaf stomatal density and ABA accumulation.

Potential yield and water-use efficiency benefits in sorghum from limited maximum transpiration rate

2005 ◽  
Vol 32 (10) ◽  
pp. 945 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Graeme L. Hammer ◽  
Erik J. van Oosterom
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Transpiration Rate ◽  
Simulation Analysis ◽  
Stomatal Closure ◽  
Risk Attitude ◽  
Potential Yield ◽  
Yield Increase ◽  
Use Efficiency ◽  
Yield Responses

Limitations on maximum transpiration rates, which are commonly observed as midday stomatal closure, have been observed even under well-watered conditions. Such limitations may be caused by restricted hydraulic conductance in the plant or by limited supply of water to the plant from uptake by the roots. This behaviour would have the consequences of limiting photosynthetic rate, increasing transpiration efficiency, and conserving soil water. A key question is whether the conservation of water will be rewarded by sustained growth during seed fill and increased grain yield. This simulation analysis was undertaken to examine consequences on sorghum yield over several years when maximum transpiration rate was imposed in a model. Yields were simulated at four locations in the sorghum-growing area of Australia for 115 seasons at each location. Mean yield was increased slightly (5–7%) by setting maximum transpiration rate at 0.4 mm h–1. However, the yield increase was mainly in the dry, low-yielding years in which growers may be more economically vulnerable. In years with yield less than ∼450 g m–2, the maximum transpiration rate trait resulted in yield increases of 9–13%. At higher yield levels, decreased yields were simulated. The yield responses to restricted maximum transpiration rate were associated with an increase in efficiency of water use. This arose because transpiration was reduced at times of the day when atmospheric demand was greatest. Depending on the risk attitude of growers, incorporation of a maximum transpiration rate trait in sorghum cultivars could be desirable to increase yields in dry years and improve water use efficiency and crop yield stability.

Sign in / Sign up

Export Citation Format

Share Document