Shanghai Agrobiological Gene Center, Shanghai, China.
College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan, China.
Sci Rep. 2017 Jan 4;7:39843. doi: 10.1038/srep39843.
Epigenetic mechanisms are crucial mediators of appropriate plant reactions to adverse environments, but their involvement in long-term adaptation is less clear. Here, we established two rice epimutation accumulation lines by applying drought conditions to 11 successive generations of two rice varieties. We took advantage of recent technical advances to examine the role of DNA methylation variations on rice adaptation to drought stress. We found that multi-generational drought improved the drought adaptability of offspring in upland fields. At single-base resolution, we discovered non-random appearance of drought-induced epimutations. Moreover, we found that a high proportion of drought-induced epimutations maintained their altered DNA methylation status in advanced generations. In addition, genes related to transgenerational epimutations directly participated in stress-responsive pathways. Analysis based on a cluster of drought-responsive genes revealed that their DNA methylation patterns were affected by multi-generational drought. These results suggested that epigenetic mechanisms play important roles in rice adaptations to upland growth conditions. Epigenetic variations have morphological, physiological and ecological consequences and are heritable across generations, suggesting that epigenetics can be considered an important regulatory mechanism in plant long-term adaptation and evolution under adverse environments.
表观遗传机制是植物对不利环境做出适当反应的关键介质，但它们在长期适应中的作用尚不清楚。在这里，我们通过对两个水稻品种进行 11 代连续干旱处理，建立了两个水稻表观遗传突变积累系。我们利用最近的技术进步，研究了 DNA 甲基化变异在水稻适应干旱胁迫中的作用。我们发现，多代干旱提高了后代在旱地的耐旱性。在单碱基分辨率上，我们发现了干旱诱导的表观突变的非随机出现。此外，我们发现，在高级世代中，相当大比例的干旱诱导的表观突变保持其改变的 DNA 甲基化状态。此外，与跨代表观突变相关的基因直接参与了应激反应途径。基于一组干旱应答基因的分析表明，它们的 DNA 甲基化模式受到多代干旱的影响。这些结果表明，表观遗传机制在水稻适应旱地生长条件中发挥重要作用。表观遗传变异具有形态、生理和生态后果，并可在代际间遗传，这表明表观遗传学可以被认为是植物在不利环境下长期适应和进化的一个重要调控机制。
