高温多湿胁迫下辣椒DNA甲基化分析

Methylation-sensitive Amplified Polymorphism Analysis of DNA Methylation in Hot Pepper under High Temperature and Air Humidity Stress

研究辣椒耐高温多湿自交系597和热湿敏感自交系590在苗期高温多湿胁迫前后DNA甲基化的变化情况,探讨DNA甲基化在辣椒高温多湿胁迫反应中的作用。用甲基化敏感扩增多态性技术（methylation sensitive amplified polymorphism,MSAP）分析DNA甲基化变化情况。MSAP分析结果显示,辣椒基因组中约有64.80%～75.89%的CCGG位点发生了胞嘧啶甲基化;高温多湿胁迫4d后,耐高温多湿材料597总体甲基化率和全甲基化率均有所下降,但是热湿敏感材料590总体甲基化率和全甲基化率均有所上升;甲基化水平及状态变化存在品种差异。由此推测,DNA去甲基化是植物耐高温多湿机制的一部分,为进一步深入研究奠定基础。

This study aimed at the relationship between DNA methylation and high temperature and air humidity response in hot pepper（ Capsicum annuum L.） by characterizing DNA methylation in leaves at seedling stages for 597（ a high temperature and air humidity tolerance line） and 590（ a high temperature and air humidity sensitive line）. Methylation sensitive amplified polymorphism（ MSAP） was used to analyze genomic DNA methylation levels and patterns. Results showed that 64. 80% ～ 75. 89% of cytosine methylation were in the CCGG sequences in hot pepper genome. The total methylation ratio and full methylation ratio in pepper 597 decreased while those in pepper 590 increased after 4 days treatment with high temperature and air humidity stress. It was revealed that the level and the pattern of DNA methylation under high temperature and air humidity were variety specific and the change of DNA methylation was related to stress response. We suggested that de-methylation could be a part of the resistant mechanism of plants response to high temperature and air humidity and could be used for further research.