黄顶菊种子萌发过程中DNA甲基化的MSAP分析

为明确入侵植物黄顶菊Flaveria bidentis生长发育与DNA甲基化之间的相互关系,采用甲基化敏感扩增多态性(methylation sensitive amplification polymorphism,MSAP)方法研究了黄顶菊种子萌发过程中DNA甲基化的动态变化。结果表明,DNA甲基化与去甲基化两者共同调控黄顶菊生命初期的生长发育,且去甲基化的变化在种子萌发过程中占主导。筛选出的12对引物共扩增出998条MSAP条带,其中多态性条带为951条,多态性百分比为95.37%。黄顶菊种子萌发过程中胞嘧啶发生甲基化主要以双链甲基化形式为主,位点数为94个,而单链甲基化位点数仅为50个;多态性位点数占总位点数比率为48.95%,表明有近一半的位点发生了DNA甲基化和去甲基化的变化;发生去甲基化变化的多态性片段有73个,而发生甲基化变化的有21个,说明黄顶菊种子萌发阶段DNA甲基化的变化主要以去甲基化形式为主,且在萌发第4天后去甲基化数目持续快速上升。

Analysis of Flaveria bidentis DNA methylation during seed germination by using MSAP method

In order to find the relationship between plant growth and DNA methylation, MSAP (methylation sensitive amplification polymorphism) method was used to study the dynamic changes of the DNA methylation in Flaveria bidentis during seed germination. The results showed that both DNA methylation and demethylation played an important role in regulating early growth and development of F. bidentis, and the demethylation change was dominant. By using 12 pairs of primers, we got 998 MSAP bands, of which 951 were polymorphic bands and polymorphic percentage was 95.37%. During the seed germination of F. bidentis, cytosine methylation occurred mainly in the form of double-stranded methylation. The number of double-stranded methylation sites was 94, while the number of singlestranded methylation sites was only 50. The number of polymorphic loci accounted for 48.95% of the total site number, indicating that nearly half of the sites had DNA methylation and demethylation. Demethylation occurred in 73 polymorphic fragments, while 21 sites were methylated, indicating that DNA methylation of F. bidentis during seed germination mainly took the form of demethylation, and the number of demethylation sites continued to rise rapidly in four days.