Physiological and morphological responses to water stress in Aegilops biuncialis and Triticum aestivum genotypes with differing tolerance to drought

2004 ◽  
Vol 31 (12) ◽  
pp. 1149 ◽  
Author(s):  
István Molnár ◽  
László Gáspár ◽  
Éva Sárvári ◽  
Sándor Dulai ◽  
Borbála Hoffmann ◽  
...  
Keyword(s):  
Growth Rate ◽  
Triticum Aestivum ◽  
Water Stress ◽  
Drought Tolerance ◽  
Osmotic Stress ◽  
Biomass Production ◽  
Water Loss ◽  
Stomatal Closure ◽  
Co2 Assimilation ◽  
Wheat Genotypes

The physiological and morphological responses to water stress induced by polyethylene glycol (PEG) or by withholding water were investigated in Aegilops biuncialis Vis. genotypes differing in the annual rainfall of their habitat (1050, 550 and 225 mm year–1) and in Triticum aestivum L. wheat genotypes differing in drought tolerance. A decrease in the osmotic pressure of the nutrient solution from –0.027 to –1.8 MPa resulted in significant water loss, a low degree of stomatal closure and a decrease in the intercellular CO2 concentration (Ci) in Aegilops genotypes originating from dry habitats, while in wheat genotypes high osmotic stress increased stomatal closure, resulting in a low level of water loss and high Ci. Nevertheless, under saturating light at normal atmospheric CO2 levels, the rate of CO2 assimilation was higher for the Aegilops accessions, under high osmotic stress, than for the wheat genotypes. Moreover, in the wheat genotypes CO2 assimilation exhibited less or no O2 sensitivity. These physiological responses were manifested in changes in the growth rate and biomass production, since Aegilops (Ae550, Ae225) genotypes retained a higher growth rate (especially in the roots), biomass production and yield formation after drought stress than wheat. These results indicate that Aegilops genotypes, originating from a dry habitat have better drought tolerance than wheat, making them good candidates for improving the drought tolerance of wheat through intergeneric crossing.

scholarly journals IDENTIFICATION OF DROUGHT TOLERANT WHEAT GENOTYPES UNDER WATER DEFICIT CONDITIONS

2016 ◽  
Vol 4 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Zaid Chachar ◽  
N. A. Chachar ◽  
Q.I. Chachar ◽  
S.M Mujtaba ◽  
G.A Chachar ◽  
...  
Keyword(s):  
Water Stress ◽  
Seed Germination ◽  
Osmotic Stress ◽  
Root Length ◽  
Dry Weight ◽  
Shoot Length ◽  
Wheat Genotypes ◽  
Maximum Reduction ◽  
Drought Tolerant

Climate change is emerging phenomena and causing frequent drought which lead to scaricity of water, which ultimately nagetively affecting wheat (Triticumaestivum L.) yield all around the world. The aim of this study was to explore the potential deought tolerant wheat genotypes for candidate genes exploration. This study was conducted during the year 2014-2015 at Plant Physiology Division, Nuclear Institute of Agriculture (NIA) Tandojam. The six wheat genotypes (cv. MT-1/13, MT-2/13, MT-3/13, MT-4/13 Chakwal-86 and Khirman) were investigated for their response at germination and seedling stage under different water stress treatments (0, -0.5, -0.75 and -1.0 MPa) in controlled conditions. The results of experiments with reference to genotypes revealed that genotype Chakwal-86 shows maximum seed germination (82.58 %), while the genotype Khirman shows maximum shoot length  (7.23 cm), root length  (15.1 cm), shoot fresh wt. (5.85 g 10-1shoots), root fresh wt.  (3.45 g 10-1roots), shoot dry wt. (1.33 g 10-1shoots), root dry wt. (0.69 g 10-1roots). Among the genotypes tested Khirman and MT-4/13 are the tolerant genotypes had the potential to perform better under drought conditions, whereas  MT-4/13 and Chakwal-86 were moderate tolerant under water stress conditions. Moreover, the genotypes i.e. MT-1/13 and MT-2/13 are the sensitive genotypes under drought environment. It is concluded from present in-vitro studies that osmotic stress significantly reduced the seed germination shoot/root length fresh and dry weight in all six wheat genotypes. The maximum reduction was found at higher osmotic stress induced by PEG-6000 (-1.0 MPa) significantly.

scholarly journals Effect of PEG and mannitol to induce drought stress on seed quality and stand establishment in wheat (Triticum aestivum L.) genotypes

2021 ◽  
Vol 17 (2) ◽  
pp. 469-475
Author(s):  
S. B. Patil ◽  
Jitendra Kumar S. Hilli
Keyword(s):  
Triticum Aestivum ◽  
Drought Tolerance ◽  
Root Length ◽  
Seed Quality ◽  
Block Design ◽  
Triticum Aestivum L ◽  
Germination Percentage ◽  
Shoot Length ◽  
Seedling Vigour ◽  
Wheat Genotypes

An experiment was conducted to study the screening of wheat (Triticum aestivum L.) genotypes for drought tolerance under laboratory condition during2018 at Department of Seed Science and Technology, College of Agriculture, Vijayapura. The experiment was carried out in a factorial Complete Randomized Block Design with seven treatments replicated three times. Twenty six wheat genotypes were screened for drought tolerance using 0, 15, 30, 60 per cent polyethylene ethylene glycol 6000 (PEG6000) and 1, 2, 5 per cent mannitol solutions. Data were recorded on various seedling parameters like germination percentage, root length, shoot length, seedling dry weight and seedling vigour index. The seedling traits showed a decreasing trend in response to increased concentrations of PEG6000 and mannitol. Wheat genotype DBW-110 (98.70 %) and C-306 (92.50 %) were found to be the best genotype for screened based on germination percentage at 15 per cent PEG6000 and 5 per cent mannitol. Wheat genotypes HI-1620 (6.7 cm) and NIAW-3212 (4.5 cm) produced maximum root length, respectively at higher concentrations of PEG6000 and mannitol. The genotype HI-1620 (6.4 cm, @ 15 %; 5.4 cm, @ 5 % mannitol) showed maximum shoot length. The genotype HD-2733, DBW-14, DBW-88 showed highest reduction of seedling parameters observed at increase in osmotic stress condition.

scholarly journals Kandelia candel Thioredoxin f Confers Osmotic Stress Tolerance in Transgenic Tobacco

2020 ◽  
Vol 21 (9) ◽  
pp. 3335 ◽  
Author(s):  
Xiaoshu Jing ◽  
Jun Yao ◽  
Xujun Ma ◽  
Yanli Zhang ◽  
Yuanling Sun ◽  
...  
Keyword(s):  
Drought Stress ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Osmotic Stress ◽  
Transgenic Tobacco ◽  
Stomatal Closure ◽  
H2o2 Production ◽  
Kandelia Candel ◽  
Ros Scavenging ◽  
Thioredoxin F

Water deficit caused by osmotic stress and drought limits crop yield and tree growth worldwide. Screening and identifying candidate genes from stress-resistant species are a genetic engineering strategy to increase drought resistance. In this study, an increased concentration of mannitol resulted in elevated expression of thioredoxin f (KcTrxf) in the nonsecretor mangrove species Kandelia candel. By means of amino acid sequence and phylogenetic analysis, the mangrove Trx was classified as an f-type thioredoxin. Subcellular localization showed that KcTrxf localizes to chloroplasts. Enzymatic activity characterization revealed that KcTrxf recombinant protein possesses the disulfide reductase function. KcTrxf overexpression contributes to osmotic and drought tolerance in tobacco in terms of fresh weight, root length, malondialdehyde (MDA) content, and hydrogen peroxide (H2O2) production. KcTrxf was shown to reduce the stomatal aperture by enhancing K+ efflux in guard cells, which increased the water-retaining capacity in leaves under drought conditions. Notably, the abscisic acid (ABA) sensitivity was increased in KcTrxf-transgenic tobacco, which benefits plants exposed to drought by reducing water loss by promoting stomatal closure. KcTrxf-transgenic plants limited drought-induced H2O2 in leaves, which could reduce lipid peroxidation and retain the membrane integrity. Additionally, glutathione (GSH) contributing to reactive oxygen species (ROS) scavenging and transgenic plants are more efficient at regenerating GSH from oxidized glutathione (GSSG) under conditions of drought stress. Notably, KcTrxf-transgenic plants had increased glucose and fructose contents under drought stress conditions, presumably resulting from KcTrxf-promoted starch degradation under water stress. We conclude that KcTrxf contributes to drought tolerance by increasing the water status, by enhancing osmotic adjustment, and by maintaining ROS homeostasis in transgene plants.

scholarly journals Shoot Characterization of Isoprene and Ocimene-Emitting Transgenic Arabidopsis Plants under Contrasting Environmental Conditions

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 477 ◽  
Author(s):  
Michele Faralli ◽  
Mingai Li ◽  
Claudio Varotto
Keyword(s):  
Water Stress ◽  
Stress Tolerance ◽  
Stress Responses ◽  
Water Conservation ◽  
Transgenic Arabidopsis ◽  
Stomatal Closure ◽  
Crop Improvement ◽  
Dry Weight ◽  
Co2 Assimilation ◽  
Biotic And Abiotic Stress

Isoprenoids are among the most abundant biogenic volatile compounds (VOCs) emitted by plants, and mediate both biotic and abiotic stress responses. Here, we provide for the first time a comparative analysis of transgenic Arabidopsis lines constitutively emitting isoprene and ocimene. Transgenic lines and Columbia-0 (Col-0) Arabidopsis were characterized under optimal, water stress, and heat stress conditions. Under optimal conditions, the projected leaf area (PLA), relative growth rate, and final dry weight were generally higher in transgenics than Col-0. These traits were associated to a larger photosynthetic capacity and CO2 assimilation rate at saturating light. Isoprene and ocimene emitters displayed a moderately higher stress tolerance than Col-0, showing higher PLA and gas-exchange traits throughout the experiments. Contrasting behaviors were recorded for the two overexpressors under water stress, with isoprene emitters showing earlier stomatal closure (conservative behavior) than ocimene emitters (non-conservative behavior), which might suggest different induced strategies for water conservation and stress adaptation. Our work indicates that (i) isoprene and ocimene emitters resulted in enhanced PLA and biomass under optimal and control conditions and that (ii) a moderate stress tolerance is induced when isoprene and ocimene are constitutively emitted in Arabidopsis, thus providing evidence of their role as a potential preferable trait for crop improvement.

scholarly journals Effects of Short-term Water Stress, Hydrophilic Polymer Amendment, and Antitranspirant on Stomatal Status, Transpiration, Water Loss, and Growth in `Better Boy' Tomato Plants

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 647f-648
Author(s):  
Sanliang Gu ◽  
Sunghee Guak ◽  
Leslie H. Fuchigami ◽  
Charles H. Shin
Keyword(s):  
Growth Rate ◽  
Water Stress ◽  
Stomatal Conductance ◽  
Plant Growth ◽  
Transpiration Rate ◽  
Water Loss ◽  
Hydrophilic Polymer ◽  
Short Term ◽  
Tomato Plants ◽  
Transpirational Water Loss

Seedling plugs of `Better Boy' tomato plants (Lycopersicon esculentum Mill.) were potted in processed fiber:perlite (60:40% by volume) media amended or nonamended with either crystalline or powdered hydrophilic polymer (2.4 kg·m–3), and treated with one of the several concentrations (0, 2.5, 5, 7.5, and 10%) of antitranspirant GLK-8924, at the four true-leaf stage. Plants were either well-irrigated or subjected to short-term water stress, water withholding for 3 days, after antitranspirant GLK-8924 application. Leaf stomatal conductance, transpiration rate, whole plant transpirational water loss, and growth were depressed by short-term water stress and antitranspirant GLK-8924. In contrast, hydrophilic polymer amendment increased plant growth, resulting in higher transpirational water loss. The depression of stomatal conductance and transpiration rate by short-term water stress was reversed completely in 2 days after rewatering while the reduction of plant growth rate diminished immediately. The effects of antitranspirant GLK-8924 were nearly proportional to its concentration and lasted 8 days on stomatal conductance and transpiration rate, 4 days on plant growth rate, and throughout the experimental period on plant height and transpirational water loss. Plant growth was reduced by antitranspirant GLK-8924 possibly by closing leaf stomata. In contrast, hydrophilic polymer amendment resulted in larger plants by factors other than influences attributed to stomatal status. Hydrophilic polymer amendment did not interact with antitranspirant GLK-8924 on all variables measured. The application of antitranspirant GLK-8924 was demonstrated to be useful for regulating plant water status, plant growth and protecting plants from short-term water stress.

scholarly journals Heterologous Expression of Arabidopsis rty Enhances Drought Tolerance in Strawberry (Fragaria × ananassa Duch.)

2020 ◽  
Author(s):  
Maofu Li ◽  
Yuan Yang ◽  
Ali Raza ◽  
Shanshan Yin ◽  
Hua Wang ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Drought Tolerance ◽  
Heterologous Expression ◽  
Water Use ◽  
Water Loss ◽  
Loss Rate ◽  
Stomatal Closure ◽  
Fragaria Ananassa ◽  
Water Loss Rate ◽  
Use Efficiency

Abstract Background Strawberry ( Fragaria × ananassa Duch.) is an important fruit crop worldwide. It was particularly sensitive to drought stress because of their fibrous and shallow root systems. Mutation of Arabidopsis thaliana ROOTY ( RTY ) results in increased endogenous auxin levels and roots and shoot growth, but the effects of this gene in strawberry remain unclear. Results Here, we heterologously expressed Arabidopsis rty in strawberry plants and examined the effects of rty expression on the hormonal and physiological properties of the plants. Heterologous expression of rty induced IAA accumulation and increased the production of adventitious roots as well as trichomes on the abaxial leaf surface of the transgenic plants. Furthermore, the transgenic strawberry plants had increased ABA accumulation and stomatal closure. The transgenic strawberry plants exhibited enhanced water use efficiency and a reduced water loss rate. Additionally, peroxidase and catalase activities were significantly higher in the transgenic plants than in the untransformed controls, and the transgenic plants were more drought tolerant than the wild-type plants. Our results uncover a transgenic approaches can be used to overcome the inherent trade-off between plant growth and drought tolerance by enhancing water use efficiency and reducing water loss rate under water shortage conditions. Conclusions In this study, the rty gene improves hormone-mediated drought tolerance in transgenic strawberry. We demonstrated that the heterologous expression of rty in strawberry improved drought tolerance by promoting auxin and ABA accumulation. These phytohormones together brought about various physiological changes that improved drought tolerance via increased root production, trichome density, and stomatal closure. This study provides the basis for future genetic modifications of strawberry to improve drought tolerance.

scholarly journals Evaluation of drought-tolerance in some tropical wheat genotypes (Triticum aestivum L.) at different osmotic-stress level

2020 ◽  
Vol 5 (2) ◽  
pp. 66
Author(s):  
Muhammad Kadir ◽  
Kaimuddin Kaimuddin ◽  
Yunus Musa ◽  
Muh Farid Badaruddin ◽  
Amin Nur
Keyword(s):  
Drought Tolerance ◽  
Osmotic Stress ◽  
Abiotic Factors ◽  
Block Design ◽  
Triticum Aestivum L ◽  
Potential Donor ◽  
Wheat Varieties ◽  
Tropical Condition ◽  
Wheat Genotypes ◽  
Drought Tolerant

Abiotic factors, such as temperature and drought, are the main factors limiting the cultivation under the tropical condition. Two-stage experiments were conducted to examine the drought-tolerant potential of some wheat genotypes against the osmotic stress under the tropical condition at the Laboratory and Greenhouse of Hasanuddin University and Indonesian Cereal Research Institute. The experiments were arranged in a randomized block design with the split-plot pattern and respectively provided with four and three replications. The main plot was potential osmotic stress (0, -0. 33 , and -0.67 MPa) and the sub-plot was selected wheat genotypes (17 genotypes). The results indicates that based on the germination percentage, shoot/root ratio, proline content, stomatal behavior, and relative water content, the wheat lines of O/HP-78-A22-3-7, WBLL*2KURUKU, O/HP-6-A8-2-10, and O/HP-22-A27-1-10 are identified to have better drought-tolerance than the others genotypes based on the analysis of responses to parameters observed. The positively adaptive response of some tropical wheat genotypes to drought stress may be used as a potential donor for further development of drought-tolerant wheat varieties under the tropical climate in Indonesia. 

scholarly journals The correlations and sequence of plant stomatal, hydraulic, and wilting responses to drought

2016 ◽  
Vol 113 (46) ◽  
pp. 13098-13103 ◽  
Author(s):  
Megan K. Bartlett ◽  
Tamir Klein ◽  
Steven Jansen ◽  
Brendan Choat ◽  
Lawren Sack
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Stomatal Closure ◽  
Published Data ◽  
Plant Responses ◽  
Multiple Traits ◽  
Ecosystem Responses ◽  
General Sequence ◽  
Empirically Supported ◽  
Wide Range

Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stomatal closure, wilting, declines in hydraulic conductivity in the leaves, stems, and roots, and plant mortality for 262 woody angiosperm and 48 gymnosperm species. We evaluated the correlations among the drought tolerance traits across species, and the general sequence of water potential thresholds for these traits within individual plants. The trait correlations across species provide a framework for predicting plant responses to a wide range of water stress from one or two sampled traits, increasing the ability to rapidly characterize drought tolerance across diverse species. Analyzing these correlations also identified correlations among the leaf and stem hydraulic traits and the wilting point, or turgor loss point, beyond those expected from shared ancestry or independent associations with water stress alone. Further, on average, the angiosperm species generally exhibited a sequence of drought tolerance traits that is expected to limit severe tissue damage during drought, such as wilting and substantial stem embolism. This synthesis of the relationships among the drought tolerance traits provides crucial, empirically supported insight into representing variation in multiple traits in models of plant and ecosystem responses to drought.

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