Rice is the important crop for more than half of the world population. However, drought can have a devastating impact on rice growth and reduce yield drastically. Understanding the response of rice to drought stress is especially important for crop breeding. Previously we found that rice enhanced its tolerance to drought stresses via stress memory mechanisms. Numerous memory genes were identified to play important roles in the process. DNA methylation was reported to mediate tolerance via regulating gene expression and enhances the survival rate of rice encountering drought stress. However, how DNA methylation involved in stress memory is still not clear. In this study, genome-wide bisulphite sequencing at a single base resolution methylome profiling level was performed and analyzed in rice cultivar under recurrent drought stresses and recovery treatments. We found that rice drought stress memory-related differentially methylated regions (DMRs) showed dynamic and distinct patterns. The drought-memory DMRs may regulate Transposable elements and gene expression to cope with short-term repeated drought stresses. Our findings of drought-memory DMRs can explain mechanisms of rice drought stress memory in a new perspective on global methylome details. Using epigenetic markers to breed drought-resistant rice would become a feasible way in the future research.

水稻是世界一半以上人口的重要作物。然而，干旱会对水稻生长产生破坏性影响，并大幅降低产量。了解水稻对干旱胁迫的反应对于作物育种尤其重要。以前我们发现水稻通过胁迫记忆机制增强了对干旱胁迫的耐受性。许多记忆基因被确定在这个过程中发挥重要作用。据报道，DNA 甲基化通过调节基因表达介导耐受性，提高水稻在干旱胁迫下的存活率。然而，DNA甲基化如何参与压力记忆尚不清楚。在这项研究中，在单碱基分辨率甲基化组谱水平上进行全基因组亚硫酸氢盐测序并在反复干旱胁迫和恢复处理下对水稻品种进行分析。我们发现水稻干旱胁迫记忆相关的差异甲基化区域（DMRs）表现出动态和独特的模式。干旱记忆 DMR 可以调节转座因子和基因表达，以应对短期重复干旱胁迫。我们对干旱记忆 DMR 的发现可以从全局甲基化细节的新视角解释水稻干旱胁迫记忆的机制。利用表观遗传标记培育抗旱水稻将成为未来研究的可行途径。干旱记忆 DMR 可以调节转座因子和基因表达，以应对短期重复干旱胁迫。我们对干旱记忆 DMR 的发现可以从全局甲基化细节的新视角解释水稻干旱胁迫记忆的机制。利用表观遗传标记培育抗旱水稻将成为未来研究的可行途径。干旱记忆 DMR 可以调节转座因子和基因表达，以应对短期重复干旱胁迫。我们对干旱记忆 DMR 的发现可以从全局甲基化细节的新视角解释水稻干旱胁迫记忆的机制。利用表观遗传标记培育抗旱水稻将成为未来研究的可行途径。