scholarly journals Phenotyping stomatal closure by thermal imaging for GWAS and TWAS of water use efficiency-related genes

2021 ◽  
Author(s):  
Charles Pignon ◽  
Samuel Fernandes ◽  
Ravi Valluru ◽  
Nonoy Bandillo ◽  
Roberto Lozano ◽  
...  

Stomata allow CO2 uptake by leaves for photosynthetic assimilation at the cost of water vapor loss to the atmosphere. The opening and closing of stomata in response to fluctuations in light intensity regulate CO2 and water fluxes and are essential to maintenance of water-use efficiency (WUE). However, little is known about the genetic basis for natural variation in stomatal movement, especially in C4 crops. This is partly because the stomatal response to a change in light intensity is difficult to measure at the scale required for association studies. High-throughput thermal imaging was used to bypass the phenotyping bottleneck and assess 10 traits describing stomatal conductance (gs) before, during and after a stepwise decrease in light intensity for a diversity panel of 659 sorghum accessions. Results from thermal imaging significantly correlated with photosynthetic gas-exchange measurements. gs traits varied substantially across the population and were moderately heritable (h2 up to 0.72). An integrated genome-wide and transcriptome-wide association study (GWAS/TWAS) identified candidate genes putatively driving variation in stomatal conductance traits. Of the 239 unique candidate genes identified with greatest confidence, 77 were orthologs of Arabidopsis genes related to functions implicated in WUE, including stomatal opening/closing (24 genes), stomatal/epidermal cell development (35 genes), leaf/vasculature development (12 genes), or chlorophyll metabolism/photosynthesis (8 genes). These findings demonstrate an approach to finding genotype-to-phenotype relationships for a challenging trait as well as candidate genes for further investigation of the genetic basis of WUE in a model C4 grass for bioenergy, food, and forage production.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Annabelle Damerum ◽  
Hazel K. Smith ◽  
GJJ Clarkson ◽  
Maria José Truco ◽  
Richard W. Michelmore ◽  
...  

Abstract Background Water supply limits agricultural productivity of many crops including lettuce. Identifying cultivars within crop species that can maintain productivity with reduced water supply is a significant challenge, but central to developing resilient crops for future water-limited climates. We investigated traits known to be related to water-use efficiency (WUE) and yield in lettuce, a globally important leafy salad crop, in a recombinant inbred line (RIL) lettuce mapping population, produced from a cross between the cultivated Lactuca sativa L. cv. Salinas and its wild progenitor L. serriola L. Results Wild and cultivated lettuce differed in their WUE and we observed transgressive segregation in yield and water-use traits in the RILs. Quantitative trait loci (QTL) analysis identified genomic regions controlling these traits under well-watered and droughted conditions. QTL were detected for carbon isotope discrimination, transpiration, stomatal conductance, leaf temperature and yield, controlling 4–23 % of the phenotypic variation. A QTL hotspot was identified on chromosome 8 that controlled carbon isotope discrimination, stomatal conductance and yield under drought. Several promising candidate genes in this region were associated with WUE, including aquaporins, late embryogenesis abundant proteins, an abscisic acid-responsive element binding protein and glutathione S-transferases involved in redox homeostasis following drought stress were also identified. Conclusions For the first time, we have characterised the genetic basis of WUE of lettuce, a commercially important and water demanding crop. We have identified promising candidate genomic regions determining WUE and yield under well-watered and water-limiting conditions, providing important pre-breeding data for future lettuce selection and breeding where water productivity will be a key target.


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 ◽  
...  

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.


2018 ◽  
Vol 36 (1) ◽  
pp. 7-13
Author(s):  
Melissa C. Smith ◽  
Richard N. Mack

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.


2021 ◽  
Author(s):  
Fasih Ullah Haider ◽  
Muhammad Farooq ◽  
Muhammad Naveed ◽  
Sardar Alam Cheema ◽  
Noor ul Ain ◽  
...  

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.


Author(s):  
Juan D. Franco‐Navarro ◽  
Miguel A. Rosales ◽  
Paloma Cubero‐Font ◽  
Purificación Calvo ◽  
Rosario Álvarez ◽  
...  

2014 ◽  
Vol 94 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Olanike Aladenola ◽  
Chandra Madramootoo

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.


2009 ◽  
Vol 8 (11) ◽  
pp. 1312-1320 ◽  
Author(s):  
Bian-jiang ZHANG ◽  
Quan-zhan CHEN ◽  
Chun HUA ◽  
Feng ZHOU ◽  
Quan-chen ZHOU ◽  
...  

2012 ◽  
Vol 2 (2) ◽  
pp. 71-79 ◽  
Author(s):  
Anatoly Kosobryukhov ◽  
Evgeniya Markovskaya ◽  
Liudmila Sergienko

CO2 gas exchange, transpiration, stomatal conductance, water use efficiency and chlorophyll content were investigated at the leaves of three species of the family Plantaginaceae: Plantago maritima L., Plantago subpolaris Andrejev and Plantago schrenkii C.Koch under natural conditions of the habitat on high and low tide areas of the White Sea’ coasts. The high rate of photosynthesis at saturating CO2 (PNmax) at P. maritima (85.0±4.8 μmol m-2 s-1), as compared to P. subpolaris and P. schrenkii (45.2± 7.5 and 36.9±3.2 μmol m-2 s-1) was caused by high activity of ribulose-1,5-bisphoshate carboxylase/oxygenase (RuBPCO), the rate of electron transport, the rate of triose phosphate utilization, TPU), as well as high efficiency of carboxylation. The rates of photosynthesis at ambient concentration of CO2 (PN) at P. maritima were 1.4 and 1.7 times higher compared to P. subpolaris and P. schrenkii. Plants of P. schrenkii are characterized by lower values of stomatal conductance and water use efficiency compared to P. maritima and P. subpolaris. In natural habitat, the limiting factor of CO2 assimilation P. subpolaris is the rate of photosynthetic electron transport, the activity of RuBPCO in P. schrenkii.


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