scholarly journals Rapid stomatal response to fluctuating light: an under-explored mechanism to improve drought tolerance in rice

2016 ◽  
Vol 43 (8) ◽  
pp. 727 ◽  
Author(s):  
Mingnan Qu ◽  
Saber Hamdani ◽  
Wenzhen Li ◽  
Shimei Wang ◽  
Jiuyou Tang ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Drought Tolerance ◽  
Water Use Efficiency ◽  
Water Use ◽  
A Priori ◽  
Carbon Assimilation ◽  
Co2 Uptake ◽  
Stomatal Response ◽  
Fluctuating Light ◽  
Use Efficiency

Light inside a canopy constantly fluctuates. Under fluctuating light (FL) conditions, stomatal conductance and photosynthetic rate constantly change. In this study, we explored whether this dynamics of stomata movements upon FL influenced the water use efficiency of rice in the field. We used a USDA-curated rice mini-core diversity panel consisting of 204 worldwide distributed accessions. A priori model on dynamic stomatal response to FL was utilised to identify kinetic parameters describing the stomatal delays during the closing (τcl) and the opening (τop) phase. Result showed that τcl had a larger variation than τop across the mini-core panel. τcl was negatively correlated with water use efficiency (WUE) related traits, stem diameter, grain weight per tiller and heading time, but positively correlated with maximum annual temperature, carbon assimilation related traits and biomass (P < 0.05). We further showed a strong correlation of τcl with the relative decrease of biomass under drought in 14 accessions with different τcl. We discussed the adjustment of stomatal conductance under fluctuating light in light of the trade-off between optimising CO2 uptake and optimising water saving. This study suggests that stomatal dynamics under fluctuating light is closely related to drought resistance and hence detailed study is needed to enable its application in breeding drought tolerance in rice.

scholarly journals Disentangling the role of photosynthesis and stomatal conductance on rising forest water-use efficiency

2019 ◽  
Vol 116 (34) ◽  
pp. 16909-16914 ◽  
Author(s):  
Rossella Guerrieri ◽  
Soumaya Belmecheri ◽  
Scott V. Ollinger ◽  
Heidi Asbjornsen ◽  
Katie Jennings ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Tree Ring ◽  
Carbon Assimilation ◽  
Basal Area ◽  
Atmospheric Measurements ◽  
Physiological Mechanisms ◽  
Carbon And Oxygen Isotope ◽  
Use Efficiency

Multiple lines of evidence suggest that plant water-use efficiency (WUE)—the ratio of carbon assimilation to water loss—has increased in recent decades. Although rising atmospheric CO2 has been proposed as the principal cause, the underlying physiological mechanisms are still being debated, and implications for the global water cycle remain uncertain. Here, we addressed this gap using 30-y tree ring records of carbon and oxygen isotope measurements and basal area increment from 12 species in 8 North American mature temperate forests. Our goal was to separate the contributions of enhanced photosynthesis and reduced stomatal conductance to WUE trends and to assess consistency between multiple commonly used methods for estimating WUE. Our results show that tree ring-derived estimates of increases in WUE are consistent with estimates from atmospheric measurements and predictions based on an optimal balancing of carbon gains and water costs, but are lower than those based on ecosystem-scale flux observations. Although both physiological mechanisms contributed to rising WUE, enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to species that experienced moisture limitations. This finding challenges the hypothesis that rising WUE in forests is primarily the result of widespread, CO2-induced reductions in stomatal conductance.

scholarly journals Drivers of Natural Variation in Water-Use Efficiency Under Fluctuating Light Are Promising Targets for Improvement in Sorghum

2021 ◽  
Vol 12 ◽  
Author(s):  
Charles P. Pignon ◽  
Andrew D. B. Leakey ◽  
Stephen P. Long ◽  
Johannes Kromdijk
Keyword(s):  
Steady State ◽  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Plant Performance ◽  
Fluctuating Light ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Natural Diversity ◽  
Highly Correlated

Improving leaf intrinsic water-use efficiency (iWUE), the ratio of photosynthetic CO2 assimilation to stomatal conductance, could decrease crop freshwater consumption. iWUE has primarily been studied under steady-state light, but light in crop stands rapidly fluctuates. Leaf responses to these fluctuations substantially affect overall plant performance. Notably, photosynthesis responds faster than stomata to decreases in light intensity: this desynchronization results in substantial loss of iWUE. Traits that could improve iWUE under fluctuating light, such as faster stomatal movement to better synchronize stomata with photosynthesis, show significant natural diversity in C3 species. However, C4 crops have been less closely investigated. Additionally, while modification of photosynthetic or stomatal traits independent of one another will theoretically have a proportionate effect on iWUE, in reality these traits are inter-dependent. It is unclear how interactions between photosynthesis and stomata affect natural diversity in iWUE, and whether some traits are more tractable drivers to improve iWUE. Here, measurements of photosynthesis, stomatal conductance and iWUE under steady-state and fluctuating light, along with stomatal patterning, were obtained in 18 field-grown accessions of the C4 crop sorghum. These traits showed significant natural diversity but were highly correlated, with important implications for improvement of iWUE. Some features, such as gradual responses of photosynthesis to decreases in light, appeared promising for improvement of iWUE. Other traits showed tradeoffs that negated benefits to iWUE, e.g., accessions with faster stomatal responses to decreases in light, expected to benefit iWUE, also displayed more abrupt losses in photosynthesis, resulting in overall lower iWUE. Genetic engineering might be needed to break these natural tradeoffs and achieve optimal trait combinations, e.g., leaves with fewer, smaller stomata, more sensitive to changes in photosynthesis. Traits describing iWUE at steady-state, and the change in iWUE following decreases in light, were important contributors to overall iWUE under fluctuating light.

Boron Supply and Water Deficit Consequences in Young Paricá (Schizolobium parahyba var. amazonicum) Plants

2016 ◽  
Vol 44 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Bianca do Carmo SILVA ◽  
Pêola Reis de SOUZA ◽  
Daihany Moraes CALLEGARI ◽  
Vanessa Ferreira ALVES ◽  
Allan Klynger da Silva LOBATO ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Deficit ◽  
Water Use ◽  
Electrolyte Leakage ◽  
Tolerance Mechanism ◽  
Schizolobium Parahyba ◽  
Use Efficiency

Boron (B) is a very important nutrient required by forest plants; when supplied in adequate amounts, plants can ameliorate the negative effects of abiotic stresses. The objective of this study was to (i) investigate gas exchange, (ii) measure oxidant and antioxidant compounds, and (iii) respond how B supply acts on tolerance mechanism to water deficit in young Schizolobium parahyba plants. The experiment employed a factorial that was entirely randomised, with two boron levels (25 and 250 µmol L-1, simulating conditions of sufficient B and high B, respectively) and two water conditions (control and water deficit). Water deficit induced negative modifications on net photosynthetic rate, stomatal conductance and water use efficiency, while B high promoted intensification of the effects on stomatal conductance and water use efficiency. Hydrogen peroxide and electrolyte leakage of both tissues suffered non-significant increases after B high and when applied water deficit. Ascorbate levels presented increases after water deficit and B high to leaf and root. Our results suggested that the tolerance mechanism to water deficit in young Schizolobium parahyba plants is coupled to increases in total glutathione and ascorbate aiming to control the overproduction of hydrogen peroxide and alleviates the negative consequences on electrolyte leakage and gas exchange. In relation to B supply, this study proved that sufficient level promoted better responses under control and water deficit conditions.

scholarly journals Characterization of wheat genotypes for drought tolerance and water use efficiency

2021 ◽  
Vol 78 (5) ◽  
Author(s):  
Guilherme Filgueiras Soares ◽  
Walter Quadros Ribeiro Júnior ◽  
Lucas Felisberto Pereira ◽  
Cristiane Andréa de Lima ◽  
Daiane dos Santos Soares ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Wheat Genotypes ◽  
Use Efficiency

scholarly journals Apparent Tolerance of Low Water Availability in Temperate Asian Bamboos1

2018 ◽  
Vol 36 (1) ◽  
pp. 7-13
Author(s):  
Melissa C. Smith ◽  
Richard N. Mack
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
North American ◽  
Water Availability ◽  
Irrigation Treatment ◽  
Bamboo Species ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Pleioblastus Chino

Abstract Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia but play only an incidental role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.

Influence of biochar and microorganisms co-application on the remediation and maize productivity in cadmium-contaminated soil.

2021 ◽  
Author(s):  
Fasih Ullah Haider ◽  
Muhammad Farooq ◽  
Muhammad Naveed ◽  
Sardar Alam Cheema ◽  
Noor ul Ain ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Transpiration Rate ◽  
Synergistic Effects ◽  
Photosynthesis Rate ◽  
Cow Manure ◽  
Cd Uptake ◽  
Spad Value ◽  
Use Efficiency

Abstract The synergistic effects of biochar and microorganisms on the adsorption of Cd and on cereal plant physiology remained unclear. Therefore, this experiment was performed to evaluate the combined effects of biochar pyrolyzed from (maize-straw (BC1), cow-manure (BC2), and poultry-manure (BC3), and microorganisms including (T. harzianum L. and B. subtilis L.), to evaluate, how incorporation of biochar positively influences microorganisms growth and nutrients uptake in plant, and how it mitigates under various Cd-stress levels (0, 10, and 30ppm). Cd2 (30 ppm) had the highest reduction in the intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate, which were 22.36, 34.50, 40.45, 20.66, 29.07, and 22.41% respectively lower than control Cd0 (0 ppm). Sole application BC, resulted in enhanced intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate were recorded in BC2, which were 7.27, 20.54, 23.80, 5.96, 13.37, and 13.50% respectively greater as compared to control and decreased the Cd-concentration in root and shoot of maize by 34.07 and 32.53%, respectively as compared to control. Similarly, among sole microorganism’s inoculation, minimized the Cd-concentration in shoot, root, and soil by 23.77, 20.15, and 10.35% respectively than control. These results suggested that integrated application of cow manure biochar BC2 and inoculation of microorganisms MI3 as soil amendments had synergistic effects in improving the adsorption of nutrients and decreasing the Cd-uptake in maize, and enhancing the physiology of plant grown in Cd-polluted soils as opposed to using either biochar or inoculating microorganisms alone.

scholarly journals Chloride as macronutrient increases water use efficiency by anatomically‐driven reduced stomatal conductance and increased mesophyll diffusion to CO 2

2019 ◽  
Author(s):  
Juan D. Franco‐Navarro ◽  
Miguel A. Rosales ◽  
Paloma Cubero‐Font ◽  
Purificación Calvo ◽  
Rosario Álvarez ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Use Efficiency

Response of greenhouse-grown bell pepper (Capsicum annuum L.) to variable irrigation

2014 ◽  
Vol 94 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Olanike Aladenola ◽  
Chandra Madramootoo
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Capsicum Annuum ◽  
Water Use ◽  
Irrigation Water ◽  
Bell Pepper ◽  
Marketable Yield ◽  
Capsicum Annuum L ◽  
Use Efficiency

Aladenola, O. and Madramootoo, C. 2014. Response of greenhouse-grown bell pepper (Capsicum annuum L.) to variable irrigation. Can. J. Plant Sci. 94: 303–310. In order to optimize water use in bell pepper production information about the appropriate irrigation water applications and agronomic and physiological response to mild and severe water stress is necessary. Different water applications were tested on yield, quality and water stress threshold of greenhouse-grown bell pepper (Capsicum annuum L.) cultivar Red Knight in 2011 and 2012 on the Macdonald Campus of McGill University, Ste Anne De Bellevue, QC. The study was carried out on a soil substrate in the greenhouse. Irrigation was scheduled with four treatments:120% (T1), 100% (T2), 80% (T3), and 40% (T4) replenishment of crop evapotranspiration in a completely randomized design. The highest marketable yield, water use efficiency and irrigation water use efficiency were obtained with T1 in both years. T1 received 20% more water than T2 to produce 23% more marketable yield than T2. Fruit total soluble solids content was highest in T4, and smallest in T1. The mean crop water stress index (CWSI) of the irrigation treatments ranged between 0.08 and 1.18. Leaf stomatal conductance of bell pepper was 75 to 80% lower in T4 than in T1. Regression obtained between stomatal conductance and CWSI resulted in a polynomial curve with coefficients of determination of 0.88 and 0.97 in 2011 and 2012, respectively. The result from this study indicate that the yield derived justifies the use of an extra quantity of water. Information from this study will help water regulators to make appropriate decision about water to be allocated for greenhouse production of bell pepper.

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