红麻DNA甲基化响应镉胁迫及甲基化差异基因的表达分析  

DNA methylation in response to cadmium stress and expression of different methylated genes in kenaf

作　　者：卢海 李增强 唐美琼 罗登杰 曹珊 岳娇 胡亚丽 黄震 陈涛[2] 陈鹏 LU Hai;LI Zeng-Qiang;TANG Mei-Qiong;LUO Deng-Jie;CAO Shan;YUE Jiao;HU Ya-Li;HUANG Zhen;CHEN Tao;CHEN Peng(College of Agriculture,Guangxi University/Guangxi Colleges and Universities Key Laboratory of Plant Genetics and Breeding,Nanning 530004,Guangxi,China;Guangxi Subtropical Crops Research Institute,Nanning 530004,Guangxi,China)

机构地区：[1]广西大学农学院/广西高校植物遗传育种重点实验室,广西南宁530004 [2]广西壮族自治区亚热带作物研究所,广西南宁530004

出　　处：《作物学报》2021年第12期2324-2334,共11页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31560341,31960368);国家现代农业产业技术体系建设专项(CARS-16-E14)资助。

摘　　要：DNA甲基化是植物重要的表观遗传修饰方式之一,在响应逆境胁迫中具有重要作用,但是有关镉胁迫下植物DNA甲基化水平变化的报道甚少。本研究以红麻P3A为材料,采用水培法对幼苗进行300μmol L^(-1)的CdCl_(2)处理,测定幼苗农艺性状及镉含量;利用甲基化敏感扩增多态性技术(methylation-sensitive amplification polymorphism,MSAP)分析镉胁迫下根系DNA甲基化水平变化;回收甲基化差异片段并克隆测序,采用qRT-PCR技术对DNA甲基化差异基因的表达量进行分析。结果表明,CdCl_(2)胁迫显著抑制红麻幼苗的株高、茎粗、根长、根表面积以及全鲜重。对照及镉处理下幼苗根系的DNA甲基化率分别为62.78%、68.23%,其中全甲基化率分别为37.50%、36.36%,半甲基化率分别为25.28%、31.87%,表明镉胁迫显著提高红麻幼苗根系的DNA甲基化水平。qRT-PCR分析表明,7个与抗性密切相关的DNA甲基化差异基因也存在表达量的差异,推测DNA甲基化水平变化在响应红麻镉胁迫中发挥重要作用。本结果为深入探索DNA甲基化响应植物镉胁迫的潜在机制提供了理论基础。DNA methylation is one of the important epigenetic modifications in plants and plays an important role in response to stress.However,there are few reports of the changes of DNA methylation levels in plants under cadmium stress.The seedlings of kenaf P3A were treated with 300μmol L^(-1) CdCl_(2)by hydroponics,the agronomic traits and cadmium contents were investigated.The changes of DNA methylation level of root under cadmium stress were analyzed by using methylation sensitive amplified polymorphism(MSAP)method.In addition,the differential methylation fragments were recovered,cloned,and sequenced.The relative expression levels of differential methylated genes revealed that Cd stress significantly inhibited the plant height,stem diameter,root length,root surface area,and total fresh weight of kenaf seedlings.The whole DNA methylation ratio in root was 68.23%and 62.78%under cadmium and control treatments,respectively.Among them the total methylation ratio was 37.50%and 36.36%,and the semi-methylation ratio was 25.28%and 31.87%,respectively.These results indicated that cadmium stress sig-nificantly increased the DNA methylation level of roots DNA.Seven differential methylated genes which involved in stress resistance were characterized differentially expressed under cadmium stress,suggesting that the change of DNA methylation played an important role in response to cadmium stress.This study provides a theoretical basis for further exploring the potential mechanism of DNA methylation in response to cadmium stress in plants.

关 键 词：红麻 镉胁迫 DNA甲基化 甲基化敏感扩增多态性(MSAP) 实时荧光定量PCR(qRT-PCR) 

分 类 号：S563.5[农业科学—作物学]