遮荫影响半夏DNA甲基化的MSAP分析

半夏为天南星科药用草本植物,其块茎入药,为我国一种常见的大宗中药材,市场需求量大。半夏在生长过程中遭遇高温强光易倒苗减产,遮荫可有效缓解半夏的倒苗,进而提升其块茎产量,但相关调控机制并不明确。DNA甲基化作为生物响应环境变化的一种自我修饰方式,常参与调控植物的生长发育。该研究以宿半夏为实验材料,选取自然光下生长的半夏为对照组,90%遮荫处理的半夏为实验组,对其基因组DNA甲基化进行甲基化敏感扩增多态性(MSAP)分析。结果表明,20对选扩引物共检测到617个基因位点,其中光照组占311个、遮荫组为306个。光照组和遮荫组中发生甲基化的位点分别占58.2%,71.57%,甲基化位点中全甲基化比率分别为27.65%,29.41%,表明遮荫显著诱导半夏基因组甲基化水平的提升。另外,相比光照组,遮荫促进32.51%的基因发生甲基化,同时诱导了16.25%基因去甲基化。该研究揭示了遮荫处理条件下半夏基因组的DNA甲基化变异水平,为进一步从表观遗传水平探析遮荫调控半夏生长的机制奠定了初步的理论基础。

Analysis of shading on DNA methylation by MSAP in Pinellia ternata

Pinellia ternata is a medicinal herb of Araceae,and its tubers are used as medicines.It is a common Chinese herbal medicine in China and has a large market demand.When exposing to strong light intensity and high temperature during the growth process,P.ternata withers in a phenomenon known as"sprout tumble",which largely limits tuber production.Shade can effectively delay sprout tumble formation and increase its yield,however the relevant regulation mechanism is unclear.DNA methylation,as a self-modifying response to environmental changes,is often involved in the regulation of plant growth and development.In this study,P.ternata grown under natural light and 90%shading were selected as the control group and the experimental group for genomic DNA methylation analysis by using methylate sensitive amplification polymorphism(MSAP).The results showed that a total of 617 loci were detected with 20 pairs of primers,of which 311 were in the natural light group and 306 in the shading group.The methylation sites in the light and shading groups accounted for 58.2%and 71.57%,respectively,and the methylation ratios in the methylation sites were 27.65%and 29.41%,respectively,indicating that shading significantly induced the genome DNA methylation of P.ternata.Compared to the natural light group,shading promoted 32.51%of the genes methylation,while inducing 16.25%gene demethylation.This study reveals the DNA methylation variation of P.ternata under shading conditions,which lays a preliminary theoretical foundation for further analysis of the mechanism of shading regulation of P.ternata growth from epigenetic level.