Overexpression of HvAKT1 improves drought tolerance in barley by regulating root ion homeostasis and ROS and NO signaling

2020 ◽  
Vol 71 (20) ◽  
pp. 6587-6600
Author(s):  
Xue Feng ◽  
Wenxing Liu ◽  
Fangbin Cao ◽  
Yizhou Wang ◽  
Guoping Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Molecular Mechanisms ◽  
Ion Homeostasis ◽  
Enzyme Activation ◽  
K Channel ◽  
H2o2 Production ◽  
Virus Induced Gene Silencing ◽  
K Uptake ◽  
Drought Treatment

Abstract Potassium (K+) is the major cationic inorganic nutrient utilized for osmotic regulation, cell growth, and enzyme activation in plants. Inwardly rectifying K+ channel 1 (AKT1) is the primary channel for root K+ uptake in plants, but the function of HvAKT1 in barley plants under drought stress has not been fully elucidated. In this study, we conducted evolutionary bioinformatics, biotechnological, electrophysiological, and biochemical assays to explore molecular mechanisms of HvAKT1 in response to drought in barley. The expression of HvAKT1 was significantly up-regulated by drought stress in the roots of XZ5—a drought-tolerant wild barley genotype. We isolated and functionally characterized the plasma membrane-localized HvAKT1 using Agrobacterium-mediated plant transformation and Barley stripe mosaic virus-induced gene silencing of HvAKT1 in barley. Evolutionary bioinformatics indicated that the K+ selective filter in AKT1 originated from streptophyte algae and is evolutionarily conserved in land plants. Silencing of HvAKT1 resulted in significantly decreased biomass and suppressed K+ uptake in root epidermal cells under drought treatment. Disruption of HvAKT1 decreased root H+ efflux, H+-ATPase activity, and nitric oxide (NO) synthesis, but increased hydrogen peroxide (H2O2) production in the roots under drought stress. Furthermore, we observed that overexpression of HvAKT1 improves K+ uptake and increases drought resistance in barley. Our results highlight the importance of HvAKT1 for root K+ uptake and its pleiotropic effects on root H+-ATPase, and H2O2 and NO in response to drought stress, providing new insights into the genetic basis of drought tolerance and K+ nutrition in barley.

scholarly journals Transcriptome analysis and molecular mechanism of linseed (Linum usitatissimum L.) drought tolerance under repeated drought using single-molecule long-read sequencing

2020 ◽  
Author(s):  
Wei Wang ◽  
Lei Wang ◽  
Ling Wang ◽  
Meilian Tan ◽  
Collins O. Ogutu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Single Molecule ◽  
Linum Usitatissimum ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Resistant Variety ◽  
Drought Treatment ◽  
Oil Crops ◽  
Drought Resistant

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.

scholarly journals Flavonoids improve drought tolerance of maize seedlings by regulating the homeostasis of reactive oxygen species

2021 ◽  
Author(s):  
Baozhu Li ◽  
Ruonan Fan ◽  
Guiling Sun ◽  
Ting Sun ◽  
Yanting Fan ◽  
...  
Keyword(s):  
Free Radicals ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Infrared Imaging ◽  
Oxygen Free Radicals ◽  
Transcriptome Profiling ◽  
Far Infrared ◽  
Drought Treatment ◽  
Physiological Characterization ◽  
Oxidative Damages

Abstract Background and aims As drought threatens the yield and quality of maize (Zea mays L.), it is important to dissect the molecular basis of maize drought tolerance. Flavonoids, participate in the scavenging of oxygen free radicals and alleviate stress-induced oxidative damages. This study aims to dissect the function of flavonoids in the improvement of maize drought tolerance. Methods Using far-infrared imaging screening, we previously isolated a drought overly insensitivity (doi) mutant from an ethyl methanesulfonate (EMS)-mutagenized maize library and designated it as doi57. In this study, we performed a physiological characterization and transcriptome profiling of doi57 in comparison to corresponding wild-type B73 under drought stress. Results Under drought stress, doi57 seedlings displayed lower leaf-surface temperature (LST), faster water loss, and better performance in growth than B73. Transcriptome analysis reveals that key genes involved in flavonoid biosynthesis are enriched among differentially expressed genes in doi57. In line with these results, more flavonols and less hydrogen peroxide (H2O2) were accumulated in guard cells of doi57 than in those of B73 with the decrease of soil water content (SWC). Moreover, the capacity determined from doi57 seedling extracts to scavenge oxygen free radicals was more effective than that of B73 under the drought treatment. Additionally, doi57 seedlings had higher photosynthetic rates, stomatal conductance, transpiration rates, and water use efficiency than B73 exposed to drought stress, resulting in high biomass and greater root/shoot ratios in doi57 mutant plants. Conclusion Flavonoids may facilitate maize seedling drought tolerance by lowering drought-induced oxidative damage as well regulating stomatal movement.

scholarly journals Comparing transcriptional responses to Fusarium crown rot in wheat and barley identified an important relationship between disease resistance and drought tolerance

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Z. Y. Su ◽  
J. J. Powell ◽  
S. Gao ◽  
M. Zhou ◽  
C. Liu
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Crown Rot ◽  
Differentially Expressed ◽  
Transcriptional Responses ◽  
Drought Treatment ◽  
Crop Species ◽  
Fusarium Crown Rot ◽  
Important Relationship ◽  
The Impact

Abstract Background Fusarium crown rot (FCR) is a chronic disease in cereal production worldwide. The impact of this disease is highly environmentally dependant and significant yield losses occur mainly in drought-affected crops. Results In the study reported here, we evaluated possible relationships between genes conferring FCR resistance and drought tolerance using two approaches. The first approach studied FCR induced differentially expressed genes (DEGs) targeting two barley and one wheat loci against a panel of genes curated from the literature based on known functions in drought tolerance. Of the 149 curated genes, 61.0% were responsive to FCR infection across the three loci. The second approach was a comparison of the global DEGs induced by FCR infection with the global transcriptomic responses under drought in wheat. This analysis found that approximately 48.0% of the DEGs detected one week following drought treatment and 74.4% of the DEGs detected three weeks following drought treatment were also differentially expressed between the susceptible and resistant isolines under FCR infection at one or more timepoints. As for the results from the first approach, the vast majority of common DEGs were downregulated under drought and expressed more highly in the resistant isoline than the sensitive isoline under FCR infection. Conclusions Results from this study suggest that the resistant isoline in wheat was experiencing less drought stress, which could contribute to the stronger defence response than the sensitive isoline. However, most of the genes induced by drought stress in barley were more highly expressed in the susceptible isolines than the resistant isolines under infection, indicating that genes conferring drought tolerance and FCR resistance may interact differently between these two crop species. Nevertheless, the strong relationship between FCR resistance and drought responsiveness provides further evidence indicating the possibility to enhance FCR resistance by manipulating genes conferring drought tolerance.

scholarly journals Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses

Agronomy ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 31 ◽  
Author(s):  
Mirza Hasanuzzaman ◽  
M. Bhuyan ◽  
Kamrun Nahar ◽  
Md. Hossain ◽  
Jubayer Mahmud ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Tolerance ◽  
Molecular Mechanisms ◽  
Abiotic Stress Tolerance ◽  
Ion Homeostasis ◽  
Enzyme Activation ◽  
Regulatory Function ◽  
Plant Responses ◽  
Plant Structure ◽  
Physiological Processes

Among the plant nutrients, potassium (K) is one of the vital elements required for plant growth and physiology. Potassium is not only a constituent of the plant structure but it also has a regulatory function in several biochemical processes related to protein synthesis, carbohydrate metabolism, and enzyme activation. Several physiological processes depend on K, such as stomatal regulation and photosynthesis. In recent decades, K was found to provide abiotic stress tolerance. Under salt stress, K helps to maintain ion homeostasis and to regulate the osmotic balance. Under drought stress conditions, K regulates stomatal opening and helps plants adapt to water deficits. Many reports support the notion that K enhances antioxidant defense in plants and therefore protects them from oxidative stress under various environmental adversities. In addition, this element provides some cellular signaling alone or in association with other signaling molecules and phytohormones. Although considerable progress has been made in understanding K-induced abiotic stress tolerance in plants, the exact molecular mechanisms of these protections are still under investigation. In this review, we summarized the recent literature on the biological functions of K, its uptake, its translocation, and its role in plant abiotic stress tolerance.

scholarly journals Identification of Two Novel Wheat Drought Tolerance-Related Proteins by Comparative Proteomic Analysis Combined with Virus-Induced Gene Silencing

2018 ◽  
Vol 19 (12) ◽  
pp. 4020 ◽  
Author(s):  
Xinbo Wang ◽  
Yanhua Xu ◽  
Jingjing Li ◽  
Yongzhe Ren ◽  
Zhiqiang Wang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Gene Silencing ◽  
Proteomic Analysis ◽  
Crop Yields ◽  
Stress Conditions ◽  
Virus Induced Gene Silencing ◽  
Knock Down ◽  
Comparative Proteomic Analysis ◽  
Related Proteins

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.

scholarly journals Comparative Proteomics of Root Apex and Root Elongation Zones Provides Insights into Molecular Mechanisms for Drought Stress and Recovery Adjustment in Switchgrass

Proteomes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 3 ◽  
Author(s):  
Zhujia Ye ◽  
Sasikiran Reddy Sangireddy ◽  
Chih-Li Yu ◽  
Dafeng Hui ◽  
Kevin Howe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Drought Stress ◽  
Molecular Mechanisms ◽  
Root Zone ◽  
Root Apex ◽  
Root Tip ◽  
Leaf Water Content ◽  
Severe Drought ◽  
Proteomics Data ◽  
Drought Treatment

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.

scholarly journals Transcriptomic studies reveal a key metabolic pathway contributing to a well-maintained photosynthetic system under drought stress in foxtail millet (Setaria italica L.)

2018 ◽  
Author(s):  
Weiping Shi ◽  
Jingye Cheng ◽  
Xiaojie Wen ◽  
Jixiang Wang ◽  
Guanyan Shi ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Abiotic Factors ◽  
Chlorophyll Biosynthesis ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Parental Lines

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet (Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ~20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.

scholarly journals Transcriptomic studies reveal a key metabolic pathway contributing to a well-maintained photosynthetic system under drought stress in foxtail millet (Setaria italica L.)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4752 ◽  
Author(s):  
Weiping Shi ◽  
Jingye Cheng ◽  
Xiaojie Wen ◽  
Jixiang Wang ◽  
Guanyan Shi ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Abiotic Factors ◽  
Chlorophyll Biosynthesis ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Parental Lines

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet (Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ∼20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.

scholarly journals Elucidating the Mechanisms Underlying Enhanced Drought Tolerance in Plants Mediated by Arbuscular Mycorrhizal Fungi

2021 ◽  
Vol 12 ◽  
Author(s):  
Shen Cheng ◽  
Ying-Ning Zou ◽  
Kamil Kuča ◽  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Mycorrhizal Fungi ◽  
Host Plants ◽  
Molecular Mechanisms ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Host Cells ◽  
Future Research ◽  
Symbiotic Association

Plants are often subjected to various environmental stresses during their life cycle, among which drought stress is perhaps the most significant abiotic stress limiting plant growth and development. Arbuscular mycorrhizal (AM) fungi, a group of beneficial soil fungi, can enhance the adaptability and tolerance of their host plants to drought stress after infecting plant roots and establishing a symbiotic association with their host plant. Therefore, AM fungi represent an eco-friendly strategy in sustainable agricultural systems. There is still a need, however, to better understand the complex mechanisms underlying AM fungi-mediated enhancement of plant drought tolerance to ensure their effective use. AM fungi establish well-developed, extraradical hyphae on root surfaces, and function in water absorption and the uptake and transfer of nutrients into host cells. Thus, they participate in the physiology of host plants through the function of specific genes encoded in their genome. AM fungi also modulate morphological adaptations and various physiological processes in host plants, that help to mitigate drought-induced injury and enhance drought tolerance. Several AM-specific host genes have been identified and reported to be responsible for conferring enhanced drought tolerance. This review provides an overview of the effect of drought stress on the diversity and activity of AM fungi, the symbiotic relationship that exists between AM fungi and host plants under drought stress conditions, elucidates the morphological, physiological, and molecular mechanisms underlying AM fungi-mediated enhanced drought tolerance in plants, and provides an outlook for future research.

scholarly journals Phenotypic and Genotypic Diversity for Drought Tolerance among and within Perennial Ryegrass Accessions

HortScience ◽  
2015 ◽  
Vol 50 (8) ◽  
pp. 1148-1154 ◽  
Author(s):  
Yu Cui ◽  
Jinsheng Wang ◽  
Xingchun Wang ◽  
Yiwei Jiang
Keyword(s):  
Genetic Diversity ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Genetic Distance ◽  
Perennial Ryegrass ◽  
Molecular Mechanisms ◽  
Phenotypic Diversity ◽  
Gene Diversity ◽  
Leaf Water Content ◽  
Drought Response

Perennial ryegrass (Lolium perenne L.) is a popular cool-season forage and turfgrass in temperate regions. Due to its self-incompatible and out-crossing nature, perennial ryegrass may show a high degree of heterozygosity. Perennial ryegrass generally is susceptible to drought stress, but variations of drought response of individual genotypes within a particular accession or cultivar are not well understood. The objective of this study was to characterize phenotypic diversity of drought tolerance within and among accessions in relation to genetic diversity in perennial ryegrass. Five individual genotypes from each of six accessions varying in origin and growth habits were subjected to drought stress in a greenhouse. Leaf wilting, plant height, chlorophyll fluorescence (Fv/Fm) and leaf water content (LWC) differed significantly among accessions as well as among genotypes within each accession under well-watered control and drought stress conditions. Fv/Fm was highly correlated with LWC under drought stress. Genetic diversity among and within accessions were identified by using previously characterized 23 simple sequence repeat markers. Across accessions, the mean major allele frequency, gene diversity, and heterozygosity values were 0.66, 0.43, and 0.66, respectively. Accessions with closer genetic distance generally had similar drought responses, while accessions with greater genetic distance showed distinct drought tolerance. Significant differences in drought tolerance among and within accessions, especially for individual genotypes within one accession, indicated that variations of drought response could be used for enhancing breeding programs and studying molecular mechanisms of stress tolerance in perennial ryegrass.

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