Wang Meng, Qin Lumin, Xie Chao, Li Wei, Yuan Jiarui, Kong Lina, Yu Wenlong, Xia Guangmin, Liu Shuwei
The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, PR China.
The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, PR China
Plant Cell Physiol. 2014 Jul;55(7):1354-65. doi: 10.1093/pcp/pcu059. Epub 2014 May 3.
Cytosine methylation is a well recognized epigenetic mark. Here, the methylation status of a salinity-tolerant wheat cultivar (cv. SR3, derived from a somatic hybridization event) and its progenitor parent (cv. JN177) was explored both globally and within a set of 24 genes responsive to salinity stress. A further comparison was made between DNA extracted from plants grown under control conditions and when challenged by salinity stress. The SR3 and JN177 genomes differed with respect to their global methylation level, and methylation levels were reduced by exposure to salinity stress. We found the genetic stress- (triggered by a combination of different genomes in somatic hybridization) induced methylation pattern of 13 loci in non-stressed SR3; the same 13 loci were found to undergo methylation in salinity-stressed JN177. For the salinity-responsive genes, SR3 and JN177 also showed different methylation modifications. C methylation polymorphisms induced by salinity stress were present in both the promoter and coding regions of some of the 24 selected genes, but only the former were associated with changes in transcript abundance. The expression of both TaFLS1 (encoding a flavonol synthase) and TaWRSI5 (encoding a Bowman-Birk-type protease inhibitor), which showed both a different expression and a different DNA methylation level between SR3 and JN177, enhanced the salinity tolerance of Arabidopsis thaliana. C methylation changes appear to be a common component of the plant response to stress, and methylation changes triggered by somatic hybridization may contribute to the superior salinity tolerance of SR3.
胞嘧啶甲基化是一种广为人知的表观遗传标记。在此,我们对一个耐盐小麦品种(cv. SR3,源自体细胞杂交事件)及其亲本(cv. JN177)的甲基化状态进行了全基因组和一组24个对盐胁迫有响应的基因内的研究。此外,还比较了从对照条件下生长的植物以及受到盐胁迫挑战的植物中提取的DNA。SR3和JN177基因组在整体甲基化水平上存在差异,并且暴露于盐胁迫会降低甲基化水平。我们发现非胁迫条件下的SR3中由遗传胁迫(体细胞杂交中不同基因组组合引发)诱导的13个位点的甲基化模式;在盐胁迫的JN177中也发现相同的13个位点发生甲基化。对于盐响应基因,SR3和JN177也表现出不同的甲基化修饰。盐胁迫诱导的C甲基化多态性存在于24个选定基因中的一些基因的启动子和编码区,但只有前者与转录本丰度的变化相关。TaFLS1(编码黄酮醇合酶)和TaWRSI5(编码鲍曼-伯克型蛋白酶抑制剂)在SR3和JN177之间表现出不同的表达和不同的DNA甲基化水平,它们的表达增强了拟南芥的耐盐性。C甲基化变化似乎是植物对胁迫响应的一个共同组成部分,体细胞杂交引发的甲基化变化可能有助于SR3具有优异的耐盐性。