scholarly journals Transcriptome Analysis of Drought-Resistant and Drought-Sensitive Sorghum (Sorghum bicolor) Genotypes in Response to PEG-Induced Drought Stress

2020 ◽  
Vol 21 (3) ◽  
pp. 772 ◽  
Author(s):  
Salah E. Abdel-Ghany ◽  
Fahad Ullah ◽  
Asa Ben-Hur ◽  
Anireddy S. N. Reddy

Drought is a major limiting factor of crop yields. In response to drought, plants reprogram their gene expression, which ultimately regulates a multitude of biochemical and physiological processes. The timing of this reprogramming and the nature of the drought-regulated genes in different genotypes are thought to confer differential tolerance to drought stress. Sorghum is a highly drought-tolerant crop and has been increasingly used as a model cereal to identify genes that confer tolerance. Also, there is considerable natural variation in resistance to drought in different sorghum genotypes. Here, we evaluated drought resistance in four genotypes to polyethylene glycol (PEG)-induced drought stress at the seedling stage and performed transcriptome analysis in seedlings of sorghum genotypes that are either drought-resistant or drought-sensitive to identify drought-regulated changes in gene expression that are unique to drought-resistant genotypes of sorghum. Our analysis revealed that about 180 genes are differentially regulated in response to drought stress only in drought-resistant genotypes and most of these (over 70%) are up-regulated in response to drought. Among these, about 70 genes are novel with no known function and the remaining are transcription factors, signaling and stress-related proteins implicated in drought tolerance in other crops. This study revealed a set of drought-regulated genes, including many genes encoding uncharacterized proteins that are associated with drought tolerance at the seedling stage.

2013 ◽  
Vol 138 (4) ◽  
pp. 277-282 ◽  
Author(s):  
Kemin Su ◽  
Justin Q. Moss ◽  
Guolong Zhang ◽  
Dennis L. Martin ◽  
Yanqi Wu

Drought stress is a major limiting factor for warm-season turfgrass growth during the summer in the U.S. transition zone. Genotypic variation in drought resistance exists among bermudagrasses (Cynodon sp.), but the mechanisms of drought resistance are poorly understood. Our objectives were to investigate physiological changes in three bermudagrass cultivars under a well-watered condition and drought stress. to determine expression differences in soluble protein and dehydrin of the three cultivars under well-watered and drought stress conditions, and to identify the association between dehydrin proteins and drought tolerance. Grasses included a high drought-resistant cultivar, Celebration, a low drought-resistant cultivar, Premier, and a newly released cultivar, Latitude 36. In both well-watered and drought treatments, ‘Latitude 36’ had the highest visual quality and lower or medium electrolyte leakage among three cultivars. In the drought treatment, 16- and 23-kDa dehydrin proteins were observed in ‘Latitude 36’ but not in ‘Celebration’ or ‘Premier’. Our results indicate that the 16- and 23-kDa dehydrin expressions could be associated with drought tolerance and contribute to drought tolerance in bermudagrass.


2020 ◽  
Vol 10 (5) ◽  
pp. 1657-1670
Author(s):  
Cheng He ◽  
Yicong Du ◽  
Junjie Fu ◽  
Erliang Zeng ◽  
Sunghun Park ◽  
...  

Drought stress is an important crop yield limiting factor worldwide. Plant physiological responses to drought stress are driven by changes in gene expression. While drought-responsive genes (DRGs) have been identified in maize, regulation patterns of gene expression during progressive water deficits remain to be elucidated. In this study, we generated time-series transcriptomic data from the maize inbred line B73 under well-watered and drought conditions. Comparisons between the two conditions identified 8,626 DRGs and the stages (early, middle, and late drought) at which DRGs occurred. Different functional groups of genes were regulated at the three stages. Specifically, early and middle DRGs display higher copy number variation among diverse Zea mays lines, and they exhibited stronger associations with drought tolerance as compared to late DRGs. In addition, correlation of expression between small RNAs (sRNAs) and DRGs from the same samples identified 201 negatively sRNA/DRG correlated pairs, including genes showing high levels of association with drought tolerance, such as two glutamine synthetase genes, gln2 and gln6. The characterization of dynamic gene responses to progressive drought stresses indicates important adaptive roles of early and middle DRGs, as well as roles played by sRNAs in gene expression regulation upon drought stress.


2018 ◽  
Vol 19 (12) ◽  
pp. 4020 ◽  
Author(s):  
Xinbo Wang ◽  
Yanhua Xu ◽  
Jingjing Li ◽  
Yongzhe Ren ◽  
Zhiqiang Wang ◽  
...  

Drought is a major adversity that limits crop yields. Further exploration of wheat drought tolerance-related genes is critical for the genetic improvement of drought tolerance in this crop. Here, comparative proteomic analysis of two wheat varieties, XN979 and LA379, with contrasting drought tolerance was conducted to screen for drought tolerance-related proteins/genes. Virus-induced gene silencing (VIGS) technology was used to verify the functions of candidate proteins. A total of 335 differentially abundant proteins (DAPs) were exclusively identified in the drought-tolerant variety XN979. Most DAPs were mainly involved in photosynthesis, carbon fixation, glyoxylate and dicarboxylate metabolism, and several other pathways. Two DAPs (W5DYH0 and W5ERN8), dubbed TaDrSR1 and TaDrSR2, respectively, were selected for further functional analysis using VIGS. The relative electrolyte leakage rate and malonaldehyde content increased significantly, while the relative water content and proline content significantly decreased in the TaDrSR1- and TaDrSR2-knock-down plants compared to that in non-knocked-down plants under drought stress conditions. TaDrSR1- and TaDrSR2-knock-down plants exhibited more severe drooping and wilting phenotypes than non-knocked-down plants under drought stress conditions, suggesting that the former were more sensitive to drought stress. These results indicate that TaDrSR1 and TaDrSR2 potentially play vital roles in conferring drought tolerance in common wheat.


Planta ◽  
2021 ◽  
Vol 255 (1) ◽  
Author(s):  
Kibrom B. Abreha ◽  
Muluken Enyew ◽  
Anders S. Carlsson ◽  
Ramesh R. Vetukuri ◽  
Tileye Feyissa ◽  
...  

Abstract Main conclusion Droughts negatively affect sorghum’s productivity and nutritional quality. Across its diversity centers, however, there exist resilient genotypes that function differently under drought stress at various levels, including molecular and physiological. Abstract Sorghum is an economically important and a staple food crop for over half a billion people in developing countries, mostly in arid and semi-arid regions where drought stress is a major limiting factor. Although sorghum is generally considered tolerant, drought stress still significantly hampers its productivity and nutritional quality across its major cultivation areas. Hence, understanding both the effects of the stress and plant response is indispensable for improving drought tolerance of the crop. This review aimed at enhancing our understanding and provide more insights on drought tolerance in sorghum as a contribution to the development of climate resilient sorghum cultivars. We summarized findings on the effects of drought on the growth and development of sorghum including osmotic potential that impedes germination process and embryonic structures, photosynthetic rates, and imbalance in source-sink relations that in turn affect seed filling often manifested in the form of substantial reduction in grain yield and quality. Mechanisms of sorghum response to drought-stress involving morphological, physiological, and molecular alterations are presented. We highlighted the current understanding about the genetic basis of drought tolerance in sorghum, which is important for maximizing utilization of its germplasm for development of improved cultivars. Furthermore, we discussed interactions of drought with other abiotic stresses and biotic factors, which may increase the vulnerability of the crop or enhance its tolerance to drought stress. Based on the research reviewed in this article, it appears possible to develop locally adapted cultivars of sorghum that are drought tolerant and nutrient rich using modern plant breeding techniques.


Author(s):  
M. Jincya ◽  
V. Babu Rajendra Prasad ◽  
P. Jeyakumara ◽  
A. Senthila ◽  
N. Manivannan

Drought stress is one of the major constraints for pulse production which negatively affecting its growth and production. Screening and selection of desirable genotypes for drought tolerance is the first and foremost important step in pulse breeding program. In green gram standardization for moisture stress was done under laboratory conditions using various concentration of PEG 6000 and 50% seedling mortality was observed at 0.5 MPa of moisture stress. Using this level of moisture stress 108 green gram genotypes were screened for their drought tolerance at seedling level and the following parameters viz., germination percentage, promptness index, radicle length, root length stress index, germination stress index and seed vigour were recorded. Observations revealed that the following green gram genotypes COGG 1332, VGG 16069, VGG 17003, VGG 17004, VGG 17009, VGG 17019 and VGG 17045 were found highly tolerant to moisture stress at seedling stage.


2014 ◽  
Vol 94 (4) ◽  
pp. 633-641 ◽  
Author(s):  
Wang Xing ◽  
Hongwei Zhao ◽  
Detang Zou

Xing, W., Zhao, H. and Zou, D. 2014. Detection of main-effect and epistatic QTL for yield-related traits in rice under drought stress and normal conditions. Can. J. Plant Sci. 94: 633–641. Drought-resistant cultivars play an important role in maintaining high and stable crop yields under drought-stress conditions. However, the genetic mechanism of drought resistance must first be elucidated. Therefore, 220 recombinant inbred lines from a cross between Xiaobaijingzi (upland rice) and Kongyu 131 (Oryza sativa L.) were used to identify quantitative trait loci (QTLs) for yield and yield-component traits under drought stress and control conditions in Heilongjiang and Tieli. As a result, 23 main-effect QTLs and 11 digenic interactions were detected for four traits under the above two conditions. Of the main-effect QTLs, 10 and 8 were detected under control and drought-stress conditions, respectively; and five common QTLs were observed. In addition, five QTLs were found to be responsible for the difference across the two conditions. Among all epistatic QTLs, three types of epistatic QTLs were observed: one was between two main-effect QTLs, such as qPH-3-1 and qPH-7-2; one was between one locus with and another without main-effect, e.g., qPN-4 and qPN-3-2; and one was between two loci without main-effect, e.g., qYP-6-1 and qYP-12-2. In the above epistatic examples, their recombinant genotypes tended to reduce plant height and the number of grains per panicle and increase yield, respectively. Our results provide a good foundation for designed molecular breeding of drought-resistant rice.


2021 ◽  
Vol 22 (24) ◽  
pp. 13402
Author(s):  
Fawang Liu ◽  
Tahir Ali ◽  
Zhong Liu

Asarum sieboldii Miq. is a leading economic crop and a traditional medicinal herb in China. Leaf-blade and petiole are the only aerial tissues of A. sieboldii during the vegetative growth, playing a vital role in the accumulation and transportation of biomass energy. They also act as critical indicators of drought in agricultural management, especially for crops having underground stems. During drought, variations in the morphology and gene expression of the leaves and petioles are used to control agricultural irrigation and production. Besides, such stress can also alter the differential gene expression in these tissues. However, little is known about the drought-tolerant character of the aerial parts of A. sieboldii. In this study, we examined the physiological, biochemical and transcriptomic responses to the drought stress in the leaf blades and petioles of A. sieboldii. The molecular mechanism, involving in drought stress response, was elucidated by constructing the cDNA libraries and performing transcriptomic sequencing. Under drought stress, a total of 2,912 and 2,887 unigenes were differentially expressed in the leaf blade and petiole, respectively. The detection of many transcription factors and functional genes demonstrated that multiple regulatory pathways were involved in drought tolerance. In response to drought, the leaf blade and petiole displayed a general physiological character, a higher SOD and POD activity, a higher MDA content and lower chlorophyll content. Three unigenes encoding POD were up-regulated, which can improve POD activity. Essential oil in petiole was extracted. The relative contents of methyleugenol and safrole in essential oil were increased from 0.01% to 0.05%, and 3.89% to 16.97%, respectively, while myristicin slightly reduced from 24.87% to 21.52%. Additionally, an IGS unigene, involved in eugenol biobiosynthesis, was found up-regulated under drought stress, which was predicated to be responsible for the accumulation of methyleugenol and safrole. Simple sequence repeats (SSRs) were characterized in of A. sieboldii, and a total of 5,466 SSRs were identified. Among them, mono-nucleotides were the most abundant repeat units, accounting for 44.09% followed by tri-, tetra-, penta and hexa-nucleotide repeats. Overall, the present work provides a valuable resource for the population genetics studies of A. sieboldii. Besides, it provides much genomic information for the functional dissection of the drought-resistance in A. sieboldii., which will be useful to understand the bio-regulatory mechanisms linked with drought-tolerance to enhance its yield.


2021 ◽  
Vol 146 (1) ◽  
pp. 24-32
Author(s):  
Sylvia Cherono ◽  
Charmaine Ntini ◽  
Misganaw Wassie ◽  
Mohammad Dulal Mollah ◽  
Mohammad A. Belal ◽  
...  

The protective role of melatonin in plants under abiotic stress has been reported, but little information is available on its mitigation effect on coffee (Coffea arabica) plants. The objective of this study was to determine the effect of exogenous application of 100 µM melatonin in coffee leaves under 3 months of drought stress treatment. Melatonin was found to alleviate the drought-induced damage in coffee through reducing the rate of chlorophyll degradation, electrolyte leakage, malonaldehyde content, and activating various antioxidant enzymes, such as catalase, guaiacol peroxidase, and superoxide dismutase. Melatonin application suppressed the expression of chlorophyll degradation gene PAO encoding pheophorbide a oxygenase, and upregulated the expression of photosynthetic gene RBCS2 encoding ribulose-1,5-bisphosphate oxygenase (Rubisco) protein, and a drought-related gene AREB encoding abscisic acid-responsive element binding protein. The photosynthetic efficiency of photosystem II under dark adaptation was also improved upon melatonin application in drought-stressed plants. Our results showed that both foliar spray and direct soil application of melatonin could improve drought tolerance by regulating photosynthetic efficiency and oxidative damage in C. arabica seedlings. This study provides insights in application of melatonin as a protective agent against drought stress in improvement of crop yields.


2020 ◽  
Author(s):  
Wei Wang ◽  
Lei Wang ◽  
Ling Wang ◽  
Meilian Tan ◽  
Collins O. Ogutu ◽  
...  

Abstract Background Oil flax (Linum usitatissimum L.) also as known as linseed is one of the most important oil crops in the world. Although linseed was reported to show better tolerance to abiotic stress conditions compared to other oil crops, the molecular mechanisms underlying linseed tolerance to drought stress are largely unknown. Moreover, as a result of climate change, drought dramatically reduces linseed yield and quality, but so far very little is known about how linseed coordinates the drought-resistant genes expression of response to different level of drought stress on the genome-wide level. Results To explore the transcriptional response of linseed to drought stress (DS) and repeated drought stress (RD), we first determined the drought tolerance of different linseed varieties. Then we performed full-length transcriptome sequencing of drought-resistant variety (Z141) and drought-sensitive variety (NY-17) using single-molecule real-time sequencing and RNA-sequencing under drought stress (DS) and repeated drought stress (RD) at the seedling stage. Gene Ontology (GO) enrichment analysis showed that compared with NY-17, the up-regulated genes of Z141 were enriched in more functional pathways related to plant drought tolerance under drought stress. In addition, the number of up-regulated genes in linseed under RD was more 30% than it under DS. In addition, a total of, 4,436 linseed transcription factors were identified, of these, 1,190 genes were responsive to stress treatments. Finally, the expression patterns of proline biosynthesis and DNA repair structural genes were verified by RT- PCR. Conclusions Drought tolerance of Z141 may be related to its specifically up-regulated drought tolerance genes under drought stress. Several variable physiological responses occurred in repeated than in sustained drought treatment. Sum up, this study provides a new perspective to understand the drought adaptability of linseed.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nannan Zhao ◽  
Shunli Cui ◽  
Xiukun Li ◽  
Bokuan Liu ◽  
Hongtao Deng ◽  
...  

Drought is one of the major abiotic stress factors limiting peanut production. It causes the loss of pod yield during the pod formation stage. Here, one previously identified drought-tolerant cultivar, “L422” of peanut, was stressed by drought (35 ± 5%) at pod formation stage for 5, 7, and 9 days. To analyze the drought effects on peanut, we conducted physiological and transcriptome analysis in leaves under well-watered (CK1, CK2, and CK3) and drought-stress conditions (T1, T2, and T3). By transcriptome analysis, 3,586, 6,730, and 8,054 differentially expressed genes (DEGs) were identified in “L422” at 5 days (CK1 vs T1), 7 days (CK2 vs T2), and 9 days (CK3 vs T3) of drought stress, respectively, and 2,846 genes were common DEGs among the three-time points. Furthermore, the result of weighted gene co-expression network analysis (WGCNA) revealed one significant module that was closely correlated between drought stress and physiological data. A total of 1,313 significantly up-/down-regulated genes, including 61 transcription factors, were identified in the module at three-time points throughout the drought stress stage. Additionally, six vital metabolic pathways, namely, “MAPK signaling pathway-plant,” “flavonoid biosynthesis,” “starch and sucrose metabolism,” “phenylpropanoid biosynthesis,” “glutathione metabolism,” and “plant hormone signal transduction” were enriched in “L422” under severe drought stress. Nine genes responding to drought tolerance were selected for quantitative real-time PCR (qRT-PCR) verification and the results agreed with transcriptional profile data, which reveals the reliability and accuracy of transcriptome data. Taken together, these findings could lead to a better understanding of drought tolerance and facilitate the breeding of drought-resistant peanut cultivars.


Sign in / Sign up

Export Citation Format

Share Document