Wang Wensheng, Huang Fei, Qin Qiao, Zhao Xiuqin, Li Zhikang, Fu Binying
Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Shenzhen Institute of Breeding and Innovation, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China.
Biochem Biophys Res Commun. 2015 Oct 2;465(4):790-6. doi: 10.1016/j.bbrc.2015.08.089. Epub 2015 Aug 28.
DNA methylation, which is one of the best understood epigenetic phenomena, plays an important role in plant responses to environmental stimuli. The rice introgression line IL177-103 and its recurrent parent IR64, which show contrasting salt stress tolerance, were used to characterize DNA methylation changes under salt stress and subsequent recovery using methylation-sensitive amplified polymorphism (MSAP) analysis. The introgression line IL177-103 showed significantly improved tolerance to salinity, as represented by higher relative water content, endogenous abscisic acid content, activity of reactive oxygen species scavenging enzymes, and lower Na(+) concentration in shoots, compared with IR64. The MSAP results showed that less than 10.5% of detected DNA methylation sites were genotype specific, in line with their similar genetic background. Salt-induced DNA methylation changes in both genotypes were mostly detected in roots, and the major portion of the salt-induced DNA demethylation/methylation alterations remained even after recovery, implying their inheritance in the present generation. Furthermore, a few sites with stable DNA methylation differences were identified between salt-tolerant IL177-103 and salt-sensitive IR64, thus providing genotype-specific epigenetic markers. Collectively, these results provide valuable data for further dissection of the molecular mechanisms of salt-stress response and tolerance in rice.
DNA甲基化是目前了解最为透彻的表观遗传现象之一，在植物对环境刺激的响应中发挥着重要作用。利用甲基化敏感扩增多态性（MSAP）分析，对耐盐性表现出显著差异的水稻渐渗系IL177 - 103及其轮回亲本IR64在盐胁迫及随后恢复过程中的DNA甲基化变化进行了表征。与IR64相比，渐渗系IL177 - 103表现出显著提高的耐盐性，表现为相对含水量、内源脱落酸含量、活性氧清除酶活性更高，以及地上部Na(+)浓度更低。MSAP结果表明，检测到的DNA甲基化位点中不到10.5%是基因型特异性的，这与其相似的遗传背景相符。两种基因型中盐诱导的DNA甲基化变化大多在根中检测到，并且即使在恢复后，盐诱导的DNA去甲基化/甲基化改变的主要部分仍然存在，这意味着它们在当代的遗传。此外，在耐盐的IL177 - 103和盐敏感的IR64之间鉴定出了一些具有稳定DNA甲基化差异的位点，从而提供了基因型特异性的表观遗传标记。总的来说，这些结果为进一步剖析水稻盐胁迫响应和耐受性的分子机制提供了有价值的数据。
