Expression profiling of DNA methyltransferase genes in wheat genotypes with contrasting drought tolerance (original) (raw)
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Responsive changes of DNA methylation in wheat (Triticum aestivum) under water deficit
Scientific Reports, 2020
DnA methylation plays an important role in the growth and development of plant, and would change under different environments. In this study, 5-methyl cytosine (5mC) content and methylation level exhibited tissue specificity in genomic DNA of wheat seedling, and increased significantly in leaf along with the increase of water deficit, which was especially significant in leaf of wheat AK58. Fullmethylation might dominate in genomic DNA of wheat seedling, the increase of full-methylation level under water deficit was significantly higher than that of hemi-methylation level. Under water deficit, DNA methylation of wheat seedling showed significant polymorphism, this polymorphism was always higher in root, especially was higher in root of wheat AK58. Further analysis appeared that changes of DnA methylation in wheat seedling took methylation as principle and demethylation as supplement under water deficit. Therefore, under water deficit, the degree, level and polymorphism of DNA methylation in wheat seedling showed tissue specificity and species specificity, and were higher in wheat AK58 compared with those of wheat XM13, perhaps wheat AK58 could more rapidly respond to water deficit by changes of DNA methylation, which would contribute to reveal molecular mechanism of wheat adapting to water deficit. Growth and development of plant are often influenced by environment, yet some studies indicated that plant could rapidly respond to the change of environment by epigenetic modification 1. As one important mode of epigenetic modifications, DNA methylation could regulate gene expression by changing chromatin structure, DNA conformation, DNA stability, DNA-protein interaction and so on 2. In nuclear genome of plant, about 20-30% cytosines are methylated, and levels of DNA methylation are different in all kinds of tissues, organs or stages 3-5. If DNA methylation is insufficient or increases in plant, growth and phenotype of plant might be aberrant 6-8 , for example, Arabidopsis thaliana would exhibit dwarf plant, smaller leaf, clump growth or maturity decline because of the reduction of DNA methylation, and these aberrant traits may be inherited to filial generation 9. Manning et al. found that DNA hyper-methylation of Cnr point in Tomato would inhibit the maturation of fruit and cause appearance variation of fruit, such as colorless fruit, pericarp absence, etc 6. Furthermore, level and status of DNA methylation might change under stress conditions, such as salt 10-12 , drought 13-15 , low temperature 16 , heavy metal 17 , pathogen 18 , and so on 19. Water deficit could lead to hyper-methylation in Pea and methylation level of second C in CCGG sequence increases by 40% 20 , low temperature would cause methylation and demethylation at some points of CCGG sequence in Oryza sativa 21. Under salt stress, methylation level of cytosine in CCGG sequence would increase by 0.2-17.6% in Rape seed 22 , and methylation level in Manioc would increase significantly 23. Tang et al. also found that drought might cause methylation level decrease by 10% in Ryegrass 13. Therefore, methylation state of plant could be influenced by environment, and plant can respond to different environments by the change of DNA methylation. Wheat belongs to one of important crops in the world, the quality and yield of wheat are seriously influenced by drought, some studies also showed that DNA methylation of plant would change under drought stress 13-15 , yet the relationship between DNA methylation and drought-tolerant mechanism is unclear in wheat. In order to study the response of DNA methylation to water deficit, common wheat genotype XinMai 13 (XM13) and resistant wheat genotype AiKang 58 (AK58) were selected as experimental materials in this study, the change of DNA methylation in wheat seedling under water deficit was analyzed with High Performance Liquid Chromatography (HPLC) and Methylation Sensitive Amplification Polymorphism (MSAP), which would provide reference to
Journal of Experimental Botany, 2011
An indica pyramiding line, DK151, and its recurrent parent, IR64, were evaluated under drought stress and nonstress conditions for three consecutive seasons. DK151 showed significantly improved tolerance to drought. The DNA methylation changes in DK151 and IR64 under drought stress and subsequent recovery were assessed using methylation-sensitive amplified polymorphism analysis. Our results indicate that drought-induced genome-wide DNA methylation changes accounted for ;12.1% of the total site-specific methylation differences in the rice genome. This drought-induced DNA methylation pattern showed three interesting properties. The most important one was its genotypic specificity reflected by large differences in the detected DNA methylation/demethylation sites between DK151 and IR64, which result from introgressed genomic fragments in DK151. Second, most droughtinduced methylation/demethylation sites were of two major types distinguished by their reversibility, including 70% of the sites at which drought-induced epigenetic changes were reversed to their original status after recovery, and 29% of sites at which the drought-induced DNA demethylation/methylation changes remain even after recovery. Third, the drought-induced DNA methylation alteration showed a significant level of developmental and tissue specificity. Together, these properties are expected to have contributed greatly to rice response and adaptation to drought stress. Thus, induced epigenetic changes in rice genome can be considered as a very important regulatory mechanism for rice plants to adapt to drought and possibly other environmental stresses.
DNA Methylation and Plants Response to Biotic and Abiotic Stress
Trends in Sciences
DNA methylation is a conserved epigenetic modification that regulates, stabilizes, and maintains genomic integrity. Loss of DNA methylation or aberrant patterns of DNA methylation causes abnormalities in the gene regulation of plants. DNA methylation in plants is regulated by the combined action of de novo methylation, maintenance of methylation, and demethylation. The enzymes that regulate DNA methylation in plants are different but have some homology to that of mammalian DNA methylation enzymes. DNA methylation helps to develop adaptation mechanisms towards various biotic and abiotic stresses. This paper provides a comprehensive review of the DNA methylation pathway and its role in biotic and abiotic stress tolerances in plants. HIGHLIGHTS Plants responds to the changing climatic condition via epigenetic changes - changing the gene expression patterns, without changing the DNA sequences Abiotic and biotic stress leads to the differential expression of genes; furthermore, plants ha...
Epigenetic responses to drought stress in rice (Oryza sativa L.)
Physiology and molecular biology of plants : an international journal of functional plant biology, 2013
Cytosine methylation polymorphism plays a key role in gene regulation, mainly in expression of genes in crop plants. The differential expression of cytosine methylation over drought stress response was analyzed in rice using drought susceptible but agronomically superior lines IR 20 and CO 43, and drought tolerant genotypes PL and PMK 3 and their F1 hybrids. The parents and hybrids were subjected to two moisture regimes viz., one under drought condition and another under control condition. The cytosine methylation polymorphism in genomic DNA was quantified under both the conditions at the reproductive stage of the plant using the Methylation Sensitive Amplified Polymorphism (MSAP) technique devised by Xiong et al. (261:439-446, 1999). The results depicted that under drought condition, hyper-methylation was predominant in the drought susceptible genotypes while drought tolerant genotypes presented hypo-methylation behavior. While imposing drought, spikelet sterility per cent was posi...
Response of DREB transcription factor to drought stress based on DNA methylation in wheat
2020
Background: The growth and development of wheat are seriously influenced by drought stress, and the research on drought resistance mechanism of wheat is very important. Dehydration responsive element binding protein (DREB) plays an important role in plant response to drought stress, but epigenetic regulation for gene expression of DREB transcription factor is less studied, especially the regulatory role of DNA methylation has not been reported.Results: In this research, DREB2, DREB6 and Wdreb2 were cloned from wheat in this study, their CDS sequence was composed of 732bp, 837bp or 1035bp, respectively, one 712bp intron was found in DREB6. Although AP2/EREBP domain of DREB2, DREB6 and Wdreb2 had 73.25% identity, they belong to different types of DREB transcription factor, and the expression of Wdreb2 was significantly higher, yet was the lowest in DREB2. Under drought stress, the expression of DREB2, DREB6 and Wdreb2 could be induced, but had different trends along with the increase ...
Response of wheat DREB transcription factor to drought stress based on DNA methylation
Research Square (Research Square), 2021
Background: The growth and development of wheat are seriously in uenced by drought, dehydration responsive element binding protein (DREB) plays an important role in the response of plant to drought stress, but epigenetic regulation for gene expression of DREB transcription factor is less studied, especially the regulatory role of DNA methylation has not been reported. Results: In this research, DREB2, DREB6 and Wdreb2 were cloned from wheat AK58, and one 712-bp intron was identi ed in DREB6. Although AP2/EREBP domains of DREB2, DREB6 and Wdreb2 showed 73.25% identity, they belong to different types of DREB transcription factor. Under drought stress, different transcript expression patterns of DREB2, DREB6 and Wdreb2 were observed, and their expression had tissue speci city, was obviously higher in leaves. Promoters of DREB2, DREB6 and Wdreb2 were further studied, some elements related to stresses were found, and the promoters of DREB2 and Wdreb2 were slightly methylated, but DREB6 promoter was moderately methylated. Compared with the control, the level of promoter methylation in DREB2 and DREB6 decreased after 2 h stress treatment, and then increased, which was opposite in Wdreb2 promoter, the status of promoter methylation in DREB2, DREB6 and Wdreb2 also had signi cant changes under drought stress. Further analysis showed that promoter methylation of DREB6 and Wdreb2 was negatively correlated with their expression, especially in Wdreb2. Conclusions: Our data suggest the different functions of DREB2, DREB6 and Wdreb2 in response to drought stress, and demonstrate the strong effects of promoter methylation on the regulation of Wdreb2 and DREB6 gene expression.
The Arabidopsis DNA Methylome Is Stable under Transgenerational Drought Stress
Plant Physiology, 2017
Improving the responsiveness, acclimation, and memory of plants to abiotic stress holds substantive potential for improving agriculture. An unresolved question is the involvement of chromatin marks in the memory of agriculturally relevant stresses. Such potential has spurred numerous investigations yielding both promising and conflicting results. Consequently, it remains unclear to what extent robust stress-induced DNA methylation variation can underpin stress memory. Using a slow-onset water deprivation treatment in Arabidopsis (Arabidopsis thaliana), we investigated the malleability of the DNA methylome to drought stress within a generation and under repeated drought stress over five successive generations. While drought-associated epialleles in the methylome were detected within a generation, they did not correlate with drought-responsive gene expression. Six traits were analyzed for transgenerational stress memory, and the descendants of drought-stressed lineages showed one case of memory in the form of increased seed dormancy, and that persisted one generation removed from stress. With respect to transgenerational drought stress, there were negligible conserved differentially methylated regions in drought-exposed lineages compared with unstressed lineages. Instead, the majority of observed variation was tied to stochastic or preexisting differences in the epigenome occurring at repetitive regions of the Arabidopsis genome. Furthermore, the experience of repeated drought stress was not observed to influence transgenerational epi-allele accumulation. Our findings demonstrate that, while transgenerational memory is observed in one of six traits examined, they are not associated with causative changes in the DNA methylome, which appears relatively impervious to drought stress.
Plant Science, 2018
Highlights We studied the role of DNA methylation in sesame response to two abiotic stresses Opposite DNA methylation patterns are induced by drought and waterlogging Drought and waterlogging trigger contrasting transcript level regulations in sesame High correlation between transcript level regulations and DNA methylation patterns Abstract DNA methylation is a heritable epigenetic mechanism that participates in gene regulation under abiotic stresses in plants. Sesame (Sesamum indicum) is typically considered a droughttolerant crop but highly susceptible to waterlogging, probably because of its origin in Africa or India. Understanding DNA methylation patterns under drought and waterlogging conditions can provide insights into the regulatory mechanisms underlying sesame contrasting responses to these abiotic stresses. We combined Methylation-Sensitive Amplified Polymorphism and transcriptome analyses to profile cytosine methylation patterns, transcript accumulation, and their interplay in drought-tolerant and waterlogging-tolerant sesame genotypes. Drought stress strongly induced de novo methylation (DNM) whereas most of the loci were demethylated (DM) during the recovery phase. In contrast, waterlogging stress decreased the level of methylation but during the recovery phase, both DM and DNM were concomitantly deployed. In both stresses, the levels of the differentially accumulated transcripts (DATs) highly correlated with the methylation patterns. We observed that DM was associated with an increase of DAT levels while DNM was correlated with a decrease of DAT levels. Altogether, sesame has divergent epigenetic programs that respond to drought and waterlogging stresses and an interplay among DNA methylation and transcript accumulation may partly modulate the contrasting responses to these stresses.
Morpho-physiological adaptation and DNA methylation of wheat seedlings under osmotic stress
Crop and Pasture Science, 2020
The quality and yield of wheat (Triticum aestivum L.) are dramatically affected by drought. We used morphological and physiological characteristics and degree of DNA methylation to compare the responses of two wheat cultivars under osmotic stress, and found that the two cultivars behaved differently. Root development, leaf growth, and the accumulation of proline and soluble carbohydrate in wheat cv. AK58 all showed drought tolerance. Drought tolerance of wheat cv. XM13 was mainly improved by accumulation of proline and soluble carbohydrate. The degree of DNA methylation in wheat showed tissue specificity and increased significantly in leaf tissue with increasing osmotic stress, but decreased significantly in root tissue under mild osmotic stress. In addition, changes of DNA methylation differed between two wheat cultivars under osmotic stress, and this change was especially significant in AK58. Therefore, wheat AK58 may have stronger self-adjustment ability under osmotic stress comp...