The abscisic acid receptor OsPYL6 confers drought tolerance to indica rice through dehydration avoidance and tolerance mechanisms

2020 ◽  
Author(s):  
V V Santosh Kumar ◽  
Shashank Kumar Yadav ◽  
Rakesh Kumar Verma ◽  
Sanya Shrivastava ◽  
Omprakash Ghimire ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Drought Tolerance ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Plant Development ◽  
Indica Rice ◽  
Stress Conditions ◽  
Wild Type ◽  
Rnai Silencing ◽  
Dehydration Avoidance

Abstract Abscisic acid (ABA) is a key regulator of plant development and stress tolerance. Here we report functional validation of the ABA receptor OsPYL6 by constitutive and stress-inducible overexpression and RNAi silencing, in an indica rice cultivar ‘Pusa Sugandh 2’. Overexpression of OsPYL6 conferred ABA hypersensitivity during germination and promoted total root length. Overexpression and RNAi silencing of OsPYL6 resulted in enhanced accumulation of ABA in seedlings under non-stress conditions, at least, in part through up-regulation of different 9-cis epoxycarotenoid dioxygenase (NCED )genes. This suggests that PYL6 expression is crucial for ABA homeostasis. Analysis of drought tolerance of OsPYL6 transgenic and wild type plants showed that OsPYL6 overexpression enhanced the expression of stress-responsive genes and dehydration tolerance. Transgenic rice plants overexpressing OsPYL6 with AtRD29A (Arabidopsis thaliana Responsive to Dehydration 29A) promoter also exhibited about 25% less whole plant transpiration, compared with wild type plants under drought, confirming its role in activation of dehydration avoidance mechanisms. However, overexpression of PYL6 reduced grain yield under non-stress conditions due to reduction in height, biomass, panicle branching and spikelet fertility. RNAi silencing of OsPYL6 also reduced grain yield under drought. These results showed that rice OsPYL6 is a key regulator of plant development and drought tolerance, and fine-tuning of its expression is critical for improving yield and stress tolerance.

scholarly journals Canopy Temperature and Chlorophyll Content are Effective Measures of Drought Stress Tolerance in Durum Wheat

2018 ◽  
Vol 10 (4) ◽  
pp. 575-583 ◽  
Author(s):  
Fereshteh JOKAR ◽  
Rahmatollah KARIMIZADEH ◽  
Asad MASOUMIASL ◽  
Reza AMIRI FAHLIANI
Keyword(s):  
Drought Tolerance ◽  
Durum Wheat ◽  
Stress Tolerance ◽  
Chlorophyll Content ◽  
Geometric Mean ◽  
Canopy Temperature ◽  
Stress Conditions ◽  
Tolerance Index ◽  
Wheat Varieties ◽  
Drought Tolerant

Durum wheat (Triticum durum L.) is used for the preparation of multiple food products, including pasta and bread. Its production is restricted due to diverse environmental stresses i.e. drought and heat stress. Here, comparative analysis of durum wheat varieties was done by studying canopy temperature depression (CTD) and chlorophyll content (CHL), yield and yield contributing traits to evaluate their performance under stress and low stress conditions. Twelve durum wheat genotypes were studied under stressful and low-stress conditions in Gachsaran region of Iran. CTD and CHL were measured at two stages, from the emergence of fifty percent of inflorescence (ZGS 54) to watery ripe stage (ZGS 71). According to stress tolerance index (STI), mean productivity (MP) and geometric mean productivity (GMP) indices, genotype G10 exhibited the most, while genotype G6, the least relative tolerance, respectively. Based on MP and GMP, genotype G10 was found to be drought tolerant, while genotype G2 displayed the lowest amount of MP and GMP. Therefore these genotypes are recommended to be used as genitors in artificial hybridization for improvement of drought tolerance in other cultivars. All indices had high correlation with grain yield under stress and non-stress condition, indicating more suitability of these indices for selection of resistant genotype. Results of the present study showed that among drought tolerance indices, harmonic mean (HM), GMP, CTD and modified STI index (K2STI) can be used as the most suitable indicators for screening drought tolerant cultivars.

scholarly journals Assessing Genetic Diversity of Rice Varieties under Drought Stress Conditions

2011 ◽  
Vol 3 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Mina ABARSHAHR ◽  
Babak RABIEI ◽  
Habibollah SAMIZADEH LAHIGI
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Geometric Mean ◽  
Minimum Variance ◽  
Stress Conditions ◽  
Productivity Index ◽  
Stress Index ◽  
Tolerance Index ◽  
Rice Varieties

In order to compare different rice genotypes grown under drought stress conditions a field experiment was conducted. In this study thirty different genotypes of native, breeded and upland cultivars were evaluated. Analysis of variance showed significant differences among genotypes in respect of all vegetative and morphological traits. Genotypes were devided into three groups by cluster analysis based on all studied traits with minimum variance method (Wards Method). The total average indicates significant differences among groups in respect of all morphological and physiological characteristics. In addition, eight drought stress tolerance indices including: sensitivity to stress index (SSI), drought response index (DRI), relative drought index (RDI), tolerance index (TOL), mean productivity index (MP), stress tolerance index (STI), geometric mean productivity index (GMP) and harmonic mean index (HM) were calculated according to their grain yield under drought stress and normal conditions. In general, results of this experimnet revealed that, among rice cultivars Domsephid, Deylamany, Hasansaraei, Sadri, Anbarboo and Domsiah had the highest sensitivity referring to drought stress and produced the lowest grain yield. Also, genotypes of IR24 (breeded of IRRI), Nemat, Sephidroud, Kadoos and Bejar (breeded of Iran) and Vandana, upland cultivar (originally from India) had the highest tolerance to drought stress and produced the highest grain yield. In conclusion, it was suggested that, these cultivars are suitable for drought stress conditions and are appropriate for hybridization with the aim of increasing drought tolerance.

scholarly journals Introgression of SbERD4 Gene Encodes an Early-Responsive Dehydration-Stress Protein That Confers Tolerance against Different Types of Abiotic Stresses in Transgenic Tobacco

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Rajesh Kumar Jha ◽  
Avinash Mishra
Keyword(s):  
Stress Tolerance ◽  
Abiotic Stresses ◽  
Stress Protein ◽  
Stress Conditions ◽  
Dehydration Stress ◽  
Wild Type ◽  
Salicornia Brachiata ◽  
Osmotic Stress Tolerance ◽  
Relative Water ◽  
Membrane Bound

Salicornia brachiata is an extreme halophyte that commonly grows on marsh conditions and is also considered a promising resource for drought and salt-responsive genes. To unveil a glimpse of stress endurance by plants, it is of the utmost importance to develop an understanding of stress tolerance mechanisms. ‘Early Responsive to Dehydration’ (ERD) genes are defined as a group of genes involved in stress tolerance and the development of plants. To increase this understanding, parallel to this expedited thought, a novel SbERD4 gene was cloned from S. brachiata, characterized, and functionally validated in the model plant tobacco. The study showed that SbERD4 is a plasma-membrane bound protein, and its overexpression in tobacco plants improved salinity and osmotic stress tolerance. Transgenic plants showed high relative water, chlorophylls, sugars, starch, polyphenols, proline, free amino acids, and low electrolyte leakage and H2O2 content compared to control plants (wild type and vector control) under different abiotic stress conditions. Furthermore, the transcript expression of antioxidant enzyme encoding genes NtCAT, NtSOD, NtGR, and NtAPX showed higher expression in transgenic compared to wild-type and vector controls under varying stress conditions. Overall, the overexpression of a novel early responsive to dehydration stress protein 4-encoding gene (SbERD4) enhanced the tolerance of the plant against multiple abiotic stresses. In conclusion, the overexpression of the SbERD4 gene mitigates plant physiology by enduring stress tolerance and might be considered as a promising key gene for engineering salinity and drought stress tolerance in crops.

scholarly journals Evaluation of a Hexaploid Wheat Collection (Triticum aestivum L.) under Drought Stress Conditions Using Stress Tolerance Indices

2020 ◽  
pp. 1-10
Author(s):  
Alireza Daneshvar Hosseini ◽  
Ali Dadkhodaie ◽  
Bahram Heidari ◽  
Seyed Abdolreza Kazemeini
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Geometric Mean ◽  
Triticum Aestivum L ◽  
Stress Conditions ◽  
Tolerance Index ◽  
Highly Correlated ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

Wheat is the most important crop in the world which faces the global problem of drought. Its production is affected by water deficit after pollination in arid and semi-arid regions. An experiment was conducted to assess tolerance of 39 bread wheat genotypes to end-season drought. The experimental design was Randomized Complete Block in three replications and the drought tolerance indices (SSI, STI, TOL, MP and GMP) were calculated for grain yield. The cultivar Cambin produced the highest grain yield under normal irrigation by 369.19 g m-2 while Arina had the highest yield (223.35 g m-2) under drought stress conditions. Stress tolerance (TOL) introduced Hindukesh, Iran2355 and Iran6476 as drought tolerant genotypes. Also, results showed that grain yield under stress and non-stress environments were highly correlated with the mean productivity (MP), the geometric mean productivity (GMP) and tolerance index (TOL). These genotypes could be further used in crosses for genetic studies and breeding programs for improvement tolerance to drought.

scholarly journals Water deficit stress tolerance assessment in barley cultivars using drought tolerance indices

2021 ◽  
Author(s):  
Md Habib ◽  
Md Mannan ◽  
Md Karim ◽  
Md Miah ◽  
Hari Singh
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Water Deficit ◽  
Geometric Mean ◽  
Research Work ◽  
Tolerance Index ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

Abstract Crop productivity is greatly affected by drought stress. Understanding the drought tolerance capability of the crop varieties available in a country is the foremost consideration for drought adaptation. The objective of this research work was to examine the drought tolerance potentiality of 5 cultivated barley varieties (BARI Barley5, BARI Barley6, BARI Barley7, BARI Barley8 and BARI Barley9) through calculating drought tolerance indices. A completely randomized design (CRD) with three replications was followed in the experiment, where crops were grown under control (80% of FC) and water deficit environment (50% of FC). Stress Tolerance (TOL), Mean Productivity (MP), Geometric Mean Productivity (GMP), Stress Susceptibility Index (SSI), Stress Tolerance Index (STI), Harmonic Mean (HAM), Yield Index (YI) and Yield Stability Index (YSI) were calculated based on grain yield under control and drought conditions. BARI Barley7 and BARI Barley8 were the most tolerant variety and BARI Barley9 considered as susceptible based on TOL and SSI. Drought tolerance indices like MP, HAM, GMP, TOL as well as STI were showed a high correlation with grain yield under both conditions and were recognized as appropriate indices to identify varieties with high grain yield and low sensitivity to drought stress.

scholarly journals Lack of Methylated Hopanoids Renders the Cyanobacterium Nostoc punctiforme Sensitive to Osmotic and pH Stress

2017 ◽  
Vol 83 (13) ◽  
Author(s):  
Tamsyn J. Garby ◽  
Emily D. Matys ◽  
Sarah E. Ongley ◽  
Anya Salih ◽  
Anthony W. D. Larkum ◽  
...  
Keyword(s):  
Stress Tolerance ◽  
Growth Rates ◽  
Growth Conditions ◽  
Stress Conditions ◽  
Oxygenic Photosynthesis ◽  
Filamentous Cyanobacterium ◽  
Wild Type ◽  
Nostoc Punctiforme ◽  
Oxidoreductase Activity ◽  
Content Type

ABSTRACT To investigate the function of 2-methylhopanoids in modern cyanobacteria, the hpnP gene coding for the radical S-adenosyl methionine (SAM) methylase protein that acts on the C-2 position of hopanoids was deleted from the filamentous cyanobacterium Nostoc punctiforme ATCC 29133S. The resulting ΔhpnP mutant lacked all 2-methylhopanoids but was found to produce much higher levels of two bacteriohopanepentol isomers than the wild type. Growth rates of the ΔhpnP mutant cultures were not significantly different from those of the wild type under standard growth conditions. Akinete formation was also not impeded by the absence of 2-methylhopanoids. The relative abundances of the different hopanoid structures in akinete-dominated cultures of the wild-type and ΔhpnP mutant strains were similar to those of vegetative cell-dominated cultures. However, the ΔhpnP mutant was found to have decreased growth rates under both pH and osmotic stress, confirming a role for 2-methylhopanoids in stress tolerance. Evidence of elevated photosystem II yield and NAD(P)H-dependent oxidoreductase activity in the ΔhpnP mutant under stress conditions, compared to the wild type, suggested that the absence of 2-methylhopanoids increases cellular metabolic rates under stress conditions. IMPORTANCE As the first group of organisms to develop oxygenic photosynthesis, Cyanobacteria are central to the evolutionary history of life on Earth and the subsequent oxygenation of the atmosphere. To investigate the origin of cyanobacteria and the emergence of oxygenic photosynthesis, geobiologists use biomarkers, the remnants of lipids produced by different organisms that are found in geologic sediments. 2-Methylhopanes have been considered indicative of cyanobacteria in some environmental settings, with the parent lipids 2-methylhopanoids being present in many contemporary cyanobacteria. We have created a Nostoc punctiforme ΔhpnP mutant strain that does not produce 2-methylhopanoids to assess the influence of 2-methylhopanoids on stress tolerance. Increased metabolic activity in the mutant under stress indicates compensatory alterations in metabolism in the absence of 2-methylhopanoids.

scholarly journals Evaluation of Drought Tolerance Indices for Screening Some of Corn (Zea mays L.) Cultivars under Environmental Conditions

2013 ◽  
Vol 5 (3) ◽  
pp. 388-393 ◽  
Author(s):  
Mohhamad Reza NAGHAVI ◽  
Alireza POUR ABOUGHADAREH ◽  
Marouf KHALILI
Keyword(s):  
Zea Mays ◽  
Drought Tolerance ◽  
Stress Tolerance ◽  
Zea Mays L ◽  
Stress Conditions ◽  
Tolerance Index ◽  
Drought Tolerant ◽  
Drought Tolerance Indices ◽  
Stress Susceptibility ◽  
Tolerance Indices

In order to study the effect of drought stress on eight cultivars corn (Zea mays L.), an experiment was conducted in a factorial experimental on the basis of randomized complete block design under two irrigated conditions during 2010-2011 cropping season. Twelve drought tolerance/resistance indices including stress tolerance index (STI), stress susceptibility index (SSI), tolerance index (TOL), geometric mean production (GMP), mean production (MP), yield index (YI), yield stability index (YSI), drought resistance index (DI), relative drought index (RDI), stress susceptibility percentage index (SSPI) and modified stress tolerance (K1STI and K2STI) were calculated based on grain yield under drought and irrigated conditions. Yield in stress and non-stress conditions were significantly and positively correlated with STI, GMP, MP, YI, TOL, DI, RDI, YSI, SSPI, K1STI, and K2STI and negatively correlated with SSI. Yield in stress and non-stress conditions were significantly and positively correlated with STI, GMP, MP, YI, TOL, DI, RDI, YSI, SSPI, K1STI, and K2STI and negatively correlated with SSI. Screening drought tolerant cultivars using ranking method, three dimensional plots discriminated cultivars ‘KSC720’, KSC 710GT and ‘KSC 700’ as the most drought tolerant. Cluster analysis classified the cultivars into three groups i.e., tolerant, susceptible and semi-susceptible to drought conditions. In general, Results of this study showed that among drought tolerance indices STI, YI, SSPI, K1STI, and K2STI can be used as the most suitable indicators for screening drought tolerant cultivars and ‘KSC720’, KSC 710 GT and ‘KSC 700’ had the highest tolerance to drought in our studies condition.

scholarly journals Estimation of drought tolerance among maize landraces from mini-core collection

Genetika ◽  
2014 ◽  
Vol 46 (3) ◽  
pp. 775-788 ◽  
Author(s):  
Violeta Andjelkovic ◽  
Natalija Kravic ◽  
Vojka Babic ◽  
Dragana Ignjatovic-Micic ◽  
Zoran Dumanovic ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Core Collection ◽  
High Density ◽  
Tolerance Index ◽  
Mini Core Collection ◽  
Drought Tolerant ◽  
Maize Landraces

Global climate change, its impact on stable food production in the future and possibilities to overcome the problem are the major priorities for research. Breeding varieties with increase adaptability to changing environments, together with better tolerance/resistance to abiotic stress, pest and diseases are possible solution. Maize is one of the most important crops, with high grain yield reduction induced by drought stress. In the present study twenty-six maize landraces from drought tolerant mini-core collection were tested under optimal, drought, and a combination of drought and high density stresses in the field. Morphological traits, plant height, total number of leaves, leaf length, leaf width, anthesis-silking interval and grain yield were recorded for each entry in two replications in three experiments. Besides, drought tolerant indices were evaluated to test the ability to separate more drought tolerant accessions from those with less stress tolerance. Five stress tolerance indices, including stress tolerance index (STI), mean productivity (MP), geometric mean productivity (GMP), stress susceptibility (SSI), and stress tolerance (TOL) were calculated. Data analyses revealed that STI, MP and GMP had positive and significant correlations with grain yield under all conditions. Three-dimensional diagrams displayed assignment of landraces L25, L1, L14, L3, L26, L15 and L16 to group A, based on the stress tolerance index and achieved grain yield under optimal, drought stress, and a combination of drought and high density stress. A biplot analysis efficiently separated groups of landraces with different level of drought tolerance and grain yield. Based on all obtained results, maize landraces L25, L14, L1 and L3, as the most valuable source of drought tolerance, could be recommended for further use in breeding programs.

scholarly journals Grain yield and drought tolerance indices of maize hybrids

2020 ◽  
Vol 12 (2) ◽  
pp. 376-386
Author(s):  
Dorina BONEA
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Yield ◽  
Negative Correlation ◽  
Stress Conditions ◽  
Stress Factors ◽  
Tolerance Index ◽  
Maize Hybrids ◽  
Significant Difference ◽  
Tolerance Indices

Drought is one of the major abiotic stress factors limiting crops production in Oltenia area, Romania. In order to study the response of six maize hybrids to drought stress, the trials were conducted in research field of ARDS Simnic – Craiova, during 2017-2018 (non-stressed conditions) and 2018-2019 (drought stress). Six tolerance indices including: abiotic tolerance index (ATI), stress susceptibility percentage index (SSPI), Stress tolerance index (STI), mean productivity (MP), relative drought index (RDI) and golden mean (GM), were utilized on the basis of grain yield. Results from analysis of variance showed that there is a significant difference in 1% of probability level among hybrids in terms of grain yield and tolerance indices. The yield in non-stress conditions (Yp) showed significant positive correlations with ATI, SSPI, STI and MP, and negative correlation with RDI and GM. The yield  in drought conditions (Ys) showed significant positive correlation with RDI and GM, and negative correlation with ATI and SSPI. None of the tolerance indices used could identify the high yielding hybrids under drought and non-stress conditions. Based on the ranking method, the hybrids ‘Felix’ and ‘P 9903’ were the most droughts tolerant. Therefore, they hybrids are recommended to be grown under drought prone areas and to be used as parents for breeding of drought tolerance in other cultivars.

scholarly journals Abscisic acid synergizes with sucrose to enhance grain yield and quality of rice by improving the source-sink relationship

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Tingting Chen ◽  
Guangyan Li ◽  
Mohammad Rezaul Islam ◽  
Weimeng Fu ◽  
Baohua Feng ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Grain Yield ◽  
Indica Rice ◽  
Starch Synthesis ◽  
Dry Matter Accumulation ◽  
Sucrose Transport ◽  
Yield And Quality ◽  
Grain Yield And Quality ◽  
Source Sink

Abstract Background Abscisic acid (ABA) and sucrose act as molecular signals in response to abiotic stress. However, how their synergy regulates the source-sink relationship has rarely been studied. This study aimed to reveal the mechanism underlying the synergy between ABA and sucrose on assimilates allocation to improve grain yield and quality of rice. The early indica rice cultivar Zhefu802 was selected and planted in an artificial climate chamber at 32/24 °C (day/night) under natural sunlight conditions. Sucrose and ABA were exogenously sprayed (either alone or in combination) onto rice plants at flowering and 10 days after flowering. Results ABA plus sucrose significantly improved both the grain yield and quality of rice, which was mainly a result of the higher proportion of dry matter accumulation and non-structural carbohydrates in panicles. These results were mainly ascribed to the large improvement in sucrose transport in the sheath-stems in response to the ABA plus sucrose treatment. In this process, ABA plus sucrose significantly enhanced the contents of starch, gibberellic acids, and zeatin ribosides as well as the activities and gene expression of enzymes involved in starch synthesis in grains. Additionally, remarkable increases in trehalose content and expression levels of trehalose-6-phosphate synthase1, trehalose-6-phosphate phosphatase7, and sucrose non-fermenting related protein kinase 1A were also found in grains treated with ABA plus sucrose. Conclusion The synergy between ABA and sucrose increased grain yield and quality by improving the source-sink relationship through sucrose and trehalose metabolism in grains.

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