scholarly journals Gene Profile Analysis and Molecular-Physiological Evaluation of Tomato Genotypes Under Drought Stress

Author(s):  
Rahele Ghanbari Moheb Seraj ◽  
Masoud Tohidfar ◽  
Asadollah Ahmadikhah

Identification of the differentially-expressed genes is important for clarification of the complex molecular mechanisms under drought conditions. In this experiment, transcriptome profiles of sensitive and tolerant tomato genotypes under drought stress were analyzed. Three up-regulated genes were selected, included CAB3 (Chlorophyll a-b binding protein3), SAMDC (S-adenosylmethionine decarboxylase proenzyme), and ACS9 (1-aminocyclopropane-1-carboxylate synthase 9). After bioinformatics analysis, tomato genotypes were subjected to drought stress and gene expression was determined using Real-Time-PCR. Physiological parameters of genotypes were also measured by spectrophotometer-based methods. According to the results, these three genes play a key role in stress tolerance. Expression of the CAB3 gene in both sensitive and tolerant genotypes was not significantly different compared to the control, but the SAMDC gene decreased in both genotypes and the ACS9 gene decreased in sensitive genotype and increased in tolerant genotype. The physiological analysis also showed that under stress conditions, the photosynthetic system of the plant was disrupted and the chlorophyll content was reduced, but, proline content and antioxidant enzymes activity increased, in which their quantity in the tolerant genotype was significantly higher than sensitive. Under drought stress, due to damage to the lipid membrane, Malondialdehyde content also increased, in which the sensitive genotype was more affected.

2020 ◽  
Vol 21 (5) ◽  
pp. 1781 ◽  
Author(s):  
Vijay Bhaskarla ◽  
Gaurav Zinta ◽  
Rebecca Ford ◽  
Mukesh Jain ◽  
Rajeev K. Varshney ◽  
...  

Drought adversely affects crop production across the globe. The root system immensely contributes to water management and the adaptability of plants to drought stress. In this study, drought-induced phenotypic and transcriptomic responses of two contrasting chickpea (Cicer arietinum L.) genotypes were compared at the vegetative, reproductive transition, and reproductive stages. At the vegetative stage, drought-tolerant genotype maintained higher root biomass, length, and surface area under drought stress as compared to sensitive genotype. However, at the reproductive stage, root length and surface area of tolerant genotype was lower but displayed higher root diameter than sensitive genotype. The shoot biomass of tolerant genotype was overall higher than the sensitive genotype under drought stress. RNA-seq analysis identified genotype- and developmental-stage specific differentially expressed genes (DEGs) in response to drought stress. At the vegetative stage, a total of 2161 and 1873 DEGs, and at reproductive stage 4109 and 3772 DEGs, were identified in the tolerant and sensitive genotypes, respectively. Gene ontology (GO) analysis revealed enrichment of biological categories related to cellular process, metabolic process, response to stimulus, response to abiotic stress, and response to hormones. Interestingly, the expression of stress-responsive transcription factors, kinases, ROS signaling and scavenging, transporters, root nodulation, and oxylipin biosynthesis genes were robustly upregulated in the tolerant genotype, possibly contributing to drought adaptation. Furthermore, activation/repression of hormone signaling and biosynthesis genes was observed. Overall, this study sheds new insights on drought tolerance mechanisms operating in roots with broader implications for chickpea improvement.


2017 ◽  
Vol 68 (7) ◽  
pp. 609 ◽  
Author(s):  
Xingwang Yu ◽  
Aijun Yang ◽  
Andrew T. James

Water deficit is a serious environmental stress during the soybean growth and production season in Australia. Soybean has evolved complex response mechanisms to cope with drought stress through multiple physiological processes. In this study, the roots of a previously identified drought-tolerant soybean genotype, G21210, and a sensitive genotype, Valder, were subjected to comparative proteomic analysis based on 2-dimensional electrophoresis, under mild or severe drought conditions. The analysis showed that the abundance of 179 protein spots significantly changed under stress. In total, 155 unique proteins were identified from these spots, among which 70 protein spots changed only in G2120 and 89 spots only in Valder, with 20 proteins changed in both soybean genotypes. Bioinformatics analysis revealed that these drought-induced changes in proteins were largely enriched in the biological function categories of defence response, protein synthesis, energy metabolism, amino acid metabolism and carbohydrate metabolism. For the drought-tolerant genotype, the differential abundance was decreased for 24 proteins and increased for 46 proteins. For the drought-sensitive genotype, the abundance was reduced for 46 proteins, increased for 40 proteins and changed differently for three proteins in mild and severe drought. The different patterns of change of these proteins in G2120 and Valder might be attributed to the difference in their drought-tolerance capacity. This study, combined with our previously reported proteomics study in soybean leaves, further clarifies the change in proteins under drought stress in different organs and provides a better understanding of the molecular mechanisms under drought stress in soybean production.


Author(s):  
Samar A. Omar ◽  
Nashwa A. H. Fetyan ◽  
Medhat E. Eldenary ◽  
Mohamed H. Abdelfattah ◽  
Haytham M. Abd-Elhalim ◽  
...  

Abstract Background Drought stress is one of the major abiotic stresses that adversely affect rice production. Four rice genotypes, Giza177, IR64 (as sensitive genotypes) and Vandana, Orabi3 (as tolerant genotypes) were used to screen and characterize the soil microbes associated with each genotype under drought stress. Results The soil microbes associated with the tolerant genotypes showed high drought tolerance and high levels of enzyme activity. The most drought-tolerant isolates were inoculated with the sensitive genotype Giza177 under drought conditions. Some morphological, biochemical and molecular responses of inoculated plants were estimated. Inoculated plants showed regulation of some growth and stress-related genes (COX1, AP2-EREBP, GRAM, NRAMP6, NAM, GST, DHN and three genes of expansin (EXP1, EXP2 and EXP3) under drought conditions. Expression profiling of these genes were highly induced in plants inoculated with 4E11 and were correlated with improved growth status under drought stress. Conclusion Based on this, drought-tolerant plant growth-promoting rhizobacteria (PGPRs) were associated with the drought-tolerant genotype (Orabi 3). They were related to the significant increase in soil enzymes activities (dehydrogenase, nitrogenase, urease and alkaline phosphatase) in the rhizosphere of tolerant genotype. Inoculation the drought-sensitive genotype (Giza 177) with the most drought-tolerant isolates improved the tolerance status of the sensitive rice genotype and induced the expression of some growth and stress-responsive genes. AP2-EREBP, NRAMP6, DHN and all expansin genes (EXP1, EXP2 and EXP3) were the highly induced genes in inoculated plants with 4E11 strain and the consortium of three selected strains under drought condition. Graphic abstract


2020 ◽  
Vol 71 (19) ◽  
pp. 6092-6106 ◽  
Author(s):  
Ping-Xia Zhao ◽  
Zi-Qing Miao ◽  
Jing Zhang ◽  
Si-Yan Chen ◽  
Qian-Qian Liu ◽  
...  

Abstract Drought is one of the most important environmental factors limiting plant growth and productivity. The molecular mechanisms underlying plant drought resistance are complex and not yet fully understood. Here, we show that the Arabidopsis MADS-box transcription factor AGL16 acts as a negative regulator in drought resistance by regulating stomatal density and movement. Loss-of-AGL16 mutants were more resistant to drought stress and had higher relative water content, which was attributed to lower leaf stomatal density and more sensitive stomatal closure due to higher leaf ABA levels compared with the wild type. AGL16-overexpressing lines displayed the opposite phenotypes. AGL16 is preferentially expressed in guard cells and down-regulated in response to drought stress. The expression of CYP707A3 and AAO3 in ABA metabolism and SDD1 in stomatal development was altered in agl16 and overexpression lines, making them potential targets of AGL16. Using chromatin immunoprecipitation, transient transactivation, yeast one-hybrid, and electrophoretic mobility shift assays, we demonstrated that AGL16 was able to bind the CArG motifs in the promoters of the CYP707A3, AAO3, and SDD1 and regulate their transcription, leading to altered leaf stomatal density and ABA levels. Taking our findings together, AGL16 acts as a negative regulator of drought resistance by modulating leaf stomatal density and ABA accumulation.


2007 ◽  
Vol 34 (7) ◽  
pp. 589 ◽  
Author(s):  
Tuan Ngoc Le ◽  
Cecilia K. Blomstedt ◽  
Jianbo Kuang ◽  
Jennifer Tenlen ◽  
Donald F. Gaff ◽  
...  

The desiccation tolerant grass Sporobolus stapfianus Gandoger can modulate cellular processes to prevent the imposition of irreversible damage to cellular components by water deficit. The cellular processes conferring this ability are rapidly attenuated by increased water availability. This resurrection plant can quickly restore normal metabolism. Even after loss of more than 95% of its total water content, full rehydration and growth resumption can occur within 24 h. To study the molecular mechanisms of desiccation tolerance in S. stapfianus, a cDNA library constructed from dehydration-stressed leaf tissue, was differentially screened in a manner designed to identify genes with an adaptive role in desiccation tolerance. Further characterisation of four of the genes isolated revealed they are strongly up-regulated by severe dehydration stress and only in desiccation-tolerant tissue, with three of these genes not being expressed at detectable levels in hydrated or dehydrating desiccation-sensitive tissue. The nature of the putative proteins encoded by these genes are suggestive of molecular processes associated with protecting the plant against damage caused by desiccation and include a novel LEA-like protein, and a pore-like protein that may play an important role in peroxisome function during drought stress. A third gene product has similarity to a nuclear-localised protein implicated in chromatin remodelling. In addition, a UDPglucose glucosyltransferase gene has been identified that may play a role in controlling the bioactivity of plant hormones or secondary metabolites during drought stress.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Minjie Deng ◽  
Yabing Cao ◽  
Zhenli Zhao ◽  
Lu Yang ◽  
Yanfang Zhang ◽  
...  

Understanding the role of miRNAs in regulating the molecular mechanisms responsive to drought stress was studied in Paulownia “yuza 1.” Two small RNA libraries and two degradome libraries were, respectively, constructed and sequenced in order to detect miRNAs and their target genes associated with drought stress. A total of 107 miRNAs and 42 putative target genes were identified in this study. Among them, 77 miRNAs were differentially expressed between drought-treated Paulownia “yuza 1” and the control (60 downregulated and 17 upregulated). The predicted target genes were annotated using the GO, KEGG, and Nr databases. According to the functional classification of the target genes, Paulownia “yuza 1” may respond to drought stress via plant hormone signal transduction, photosynthesis, and osmotic adjustment. Furthermore, the expression levels of seven miRNAs (ptf-miR157b, ptf-miR159b, ptf-miR398a, ptf-miR9726a, ptf-M2153, ptf-M2218, and ptf-M24a) and their corresponding target genes were validated by quantitative real-time PCR. The results provide relevant information for understanding the molecular mechanism of Paulownia resistance to drought and reference data for researching drought resistance of other trees.


Proteomes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 3 ◽  
Author(s):  
Zhujia Ye ◽  
Sasikiran Reddy Sangireddy ◽  
Chih-Li Yu ◽  
Dafeng Hui ◽  
Kevin Howe ◽  
...  

Switchgrass plants were grown in a Sandwich tube system to induce gradual drought stress by withholding watering. After 29 days, the leaf photosynthetic rate decreased significantly, compared to the control plants which were watered regularly. The drought-treated plants recovered to the same leaf water content after three days of re-watering. The root tip (1cm basal fragment, designated as RT1 hereafter) and the elongation/maturation zone (the next upper 1 cm tissue, designated as RT2 hereafter) tissues were collected at the 29th day of drought stress treatment, (named SDT for severe drought treated), after one (D1W) and three days (D3W) of re-watering. The tandem mass tags mass spectrometry-based quantitative proteomics analysis was performed to identify the proteomes, and drought-induced differentially accumulated proteins (DAPs). From RT1 tissues, 6156, 7687, and 7699 proteins were quantified, and 296, 535, and 384 DAPs were identified in the SDT, D1W, and D3W samples, respectively. From RT2 tissues, 7382, 7255, and 6883 proteins were quantified, and 393, 587, and 321 proteins DAPs were identified in the SDT, D1W, and D3W samples. Between RT1 and RT2 tissues, very few DAPs overlapped at SDT, but the number of such proteins increased during the recovery phase. A large number of hydrophilic proteins and stress-responsive proteins were induced during SDT and remained at a higher level during the recovery stages. A large number of DAPs in RT1 tissues maintained the same expression pattern throughout drought treatment and the recovery phases. The DAPs in RT1 tissues were classified in cell proliferation, mitotic cell division, and chromatin modification, and those in RT2 were placed in cell wall remodeling and cell expansion processes. This study provided information pertaining to root zone-specific proteome changes during drought and recover phases, which will allow us to select proteins (genes) as better defined targets for developing drought tolerant plants. The mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD017441.


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