Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
PLoS One. 2012;7(1):e30515. doi: 10.1371/journal.pone.0030515. Epub 2012 Jan 23.
Plants are able to acclimate to new growth conditions on a relatively short time-scale. Recently, we showed that the progeny of plants exposed to various abiotic stresses exhibited changes in genome stability, methylation patterns and stress tolerance. Here, we performed a more detailed analysis of methylation patterns in the progeny of Arabidopsis thaliana (Arabidopsis) plants exposed to 25 and 75 mM sodium chloride. We found that the majority of gene promoters exhibiting changes in methylation were hypermethylated, and this group was overrepresented by regulators of the chromatin structure. The analysis of DNA methylation at gene bodies showed that hypermethylation in the progeny of stressed plants was primarily due to changes in the 5' and 3' ends as well as in exons rather than introns. All but one hypermethylated gene tested had lower gene expression. The analysis of histone modifications in the promoters and coding sequences showed that hypermethylation and lower gene expression correlated with the enrichment of H3K9me2 and depletion of H3K9ac histones. Thus, our work demonstrated a high degree of correlation between changes in DNA methylation, histone modifications and gene expression in the progeny of salt-stressed plants.
植物能够在相对较短的时间内适应新的生长条件。最近，我们发现，暴露于各种非生物胁迫下的植物后代在基因组稳定性、甲基化模式和胁迫耐受性方面发生了变化。在这里，我们对暴露于 25 和 75 mM 氯化钠的拟南芥（Arabidopsis）植物后代的甲基化模式进行了更详细的分析。我们发现，大多数表现出甲基化变化的基因启动子被超甲基化，而这组基因主要由染色质结构调节剂组成。对基因体 DNA 甲基化的分析表明，胁迫植物后代的超甲基化主要是由于 5'和 3'末端以及外显子而非内含子的变化所致。除一个外，所有被测试的超甲基化基因的表达水平都较低。启动子和编码序列中组蛋白修饰的分析表明，超甲基化和较低的基因表达与 H3K9me2 的富集和 H3K9ac 组蛋白的耗竭相关。因此，我们的工作表明，盐胁迫植物后代中 DNA 甲基化、组蛋白修饰和基因表达之间存在高度相关性。
