番茄JMJ524基因调控SlGLD1的DNA甲基化分析

Analysis of the DNA Methylation of SlGLD1 Regulated by JMJ524 in Tomato

旨在分析番茄JMJ524基因如何通过影响Sl GLD1的DNA甲基化程度来调控其表达,从而导致番茄的赤霉素不敏感的矮化。利用生物信息学和BSP(Bisulfite sequencing PCR)分析JMJ524抑制系和野生型的Sl GLD1的DNA甲基化程度。结果显示,分离出Sl GLD1的启动子序列,发现其启动子区域含有3个GA响应的顺式作用元件;Sl GLD1的启动子区域和编码区的DNA是高度甲基化的,而且在不同组织部位和突变体中的甲基化模式是不一样的;在基因的编码区发现了两个GC岛,推测Sl GLD1的甲基化可能发生在基因的编码区;针对这两个GC岛进行的BSP分析结果表明:Sl GLD1的这两个区段的DNA Cp G是高度甲基化的,而且在JMJ524抑制系中,DNA的整体甲基化,特别是Cp G甲基化程度显著低于野生型对照M82。JMJ524抑制表达导致了Sl GLD1的基因甲基化程度降低,从而激活这个基因的表达,可能是导致番茄植株矮化的一个因素。

This work is to reveal the mechanism of JMJ524 modulatinges the Sl GLD1 expression by affecting the DNA methylation ofSl GLD1,and leading to the dwarf of tomato insensitive to gibberellin. Bioinformatics and BSP（Bisulfite sequencing PCR）were employedto analyze the DNA methylation of Sl GLD1 in inhibitory line and wild line of JMJ524. Results showed that the Sl GLD1 promoter sequencewas isolated,which contained 3 GA response cis-elements. The DNAs of Sl GLD1 promoter and coding sequence were highly methylated,moreover,the methylation pattern varied at the different tissues and mutants. Two GC islands were found in this coding region of the gene,thusit was inferred that the methylation of Sl GLD1 might happen in the region. Further,the analysis by BSP of the 2 GC islands indicated that theDNA Cp G in the 2 regions of Sl GLD1 was highly methylated. The whole methylation of DNA in the inhibitory line of JMJ524,especially Cp Gmethylation was significantly lower than wild-type M82. The inhibited expression by JMJ524 resulted in the decrease of gene methylation ofSl GLD1,therefore the expression of the gene was activated,which might be the one of factors causing the dwarf of tomato plant.