高温胁迫诱导棉花甲基化变化分析

Methylation-sensitive Amplified Polymorphism Analysis of Epigenetic Changes in Cotton (Gossypium hirsutum L.) under Heat Stress

高温对棉花造成的热胁迫,影响其生长发育与产量。DNA甲基化是表观遗传调控的重要组成部分,在高等植物的基因组表达调控中发挥着重要作用。本试验以耐高温品种苏棉16号和高温敏感品种石185为供试材料,研究棉花花铃期高温胁迫前后DNA甲基化的变化,通过甲基化敏感扩增多态性(methylation sensitive amplified polymorphism,MSAP)技术,探讨了不同温度下棉花叶片DNA甲基化水平和甲基化模式变化。结果显示,经过高温处理后,耐高温棉花品种苏棉16号和高温敏感棉花品种石185的甲基化水平都表现为上升,苏棉16号半甲基化率高于全甲基化率,而石185全甲基化率高于半甲基化率;棉花在受到高温胁迫后,甲基化和去甲基化同时发生,但耐高温品种苏棉16号主要发生甲基化,高温敏感品种石185主要发生去甲基化。本研究结果表明高温能够诱导棉花甲基化水平的提高,同时DNA甲基化水平及状态变化与棉花耐热性存在重要关系。

High temperature results in heat stress, which would affect the growth and development of cotton.DNA methylation is an important component of the epigenetic regulation, and plays a very important role in the regulation of gene expression in higher plants. In this study, the heat-tolerant cultivar Sumian 16 and the heatsensitive cultivar Shi 185 were applied as materials to study the DNA methylation of cotton before and after high temperature treatment. The methylation sensitive amplified polymorphism（MSAP） technique was used to study the variations of the DNA methylation level and methylation pattern of cotton leaves under heat stress. The results showed that the methylation level of heat-tolerant cultivar Sumian 16 and heat-sensitive cultivar Shi 185 was increased, and the semi-methylation rate of Sumian 16 was higher than that of full methylation, while Shi 185 was just the opposite. The methylation and desmethylation of cotton were investigated at the same time, however, the heattolerant cultivar Sumian 16 was mainly expressed as being methylated and the demethylation was mainly occurred in the heat-sensitive cultivar Shi 185. The results indicated that high temperature could improve the methylation level of cotton, and the change of DNA methylation level and status was closely involved in cotton heat tolerance.