Abstract:

Environmental stress can cause changes of DNA methylation and histone modification in plants, which play important roles in regulation of gene expression. OsDDM1a and OsDDM1b, encoding chromatin remodeling enzymes, belong to SWI2/SNF2 family, and their amino acid sequence identity is up to 92.82%. They could be induced by ABA, NaCl, low temperature and drought stress. Several important cis-elements present were found in their promoter sequences, including ABRE、DRE、MYC and WRKY, which play key roles in response to environmental stress. Therefore, rice might change its level of DNA methylation by activating the expression of OsDDM1a and OsDDM1b in response to various environmental stresses, implying these 2 genes have pivotal function in stress tolerance.

Key words: abiotic stress, OsDDM1a, OsDDM1b, DNA methylation, rice

摘要：

环境胁迫会引起植物基因组DNA甲基化水平改变和组蛋白修饰变化,而DNA甲基化与组蛋白修饰在基因表达的调控过程中具有重要作用。分析表明水稻OsDDM1a和OsDDM1b基因属于SWI2/SNF2家族,编码染色质重塑酶,氨基酸序列的相似性达92.82%。OsDDM1a和OsDDM1b的表达均受ABA、NaCl、低温和干旱胁迫诱导,且这两个基因的启动子序列中均含有ABRE、DRE、MYC和WRKY等应答不同胁迫信号的元件。因此,推测水稻在感受外界刺激后可能通过激活OsDDM1a和OsDDM1b的表达,使水稻基因组DNA发生相应的甲基化修饰,进而调控相关基因的表达,表明OsDDM1a和OsDDM1b在水稻胁迫应答反应中发挥重要的作用。

关键词: 干旱胁迫;OsDDM1a;OsDDM1b;DNA甲基化;水稻