运用MSAP研究镉胁迫对拟南芥幼苗基因甲基化的影响  

Studying Genomic Methylation of Arabidopsis thaliana Seedlings Under Cadmium Stress Using MSAP

作　　者：李照令[1,2] 王鹤潼[1] 陈瑞娟[1,2] 贾春云 李晓军[1] 台培东[1] 李培军[1] 刘宛[1] 

机构地区：[1]中国科学院沈阳应用生态研究所污染生态与环境工程重点实验室,沈阳110016 [2]中国科学院大学,北京100049

出　　处：《农业环境科学学报》2014年第1期28-36,共9页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(21347007);国家自然科学基金项目(2107 7113;40930739;20977095);辽宁省自然科学基金项目(201202224);国家科技重大专项(2012ZX07505-001);沈阳大学区域污染环境生态修复教育部重点实验室基金

摘　　要：DNA甲基化是表观遗传学的重要组成部分,并在环境胁迫响应中起重要作用。运用甲基化敏感扩增多态性(Methylation sensitive amplification polymorphism,MSAP)技术研究0、0.5、1.5、5.0 mg·L-1Cd2+处理对拟南芥幼苗全基因组DNA甲基化水平的影响,结果表明:(1)不同浓度镉处理19 d后,叶片数、地上部鲜重无明显变化,但根长受到显著抑制;(2)选取10对引物扩增DNA酶切产物,所得三个镉处理造成的拟南芥基因组MSAP%均高于对照(35%);(3)随着镉处理的增大,拟南芥基因组甲基化(M)型条带依次减少,去甲基化(D)型条带逐渐增加,并且条带亮度也有所变化;(4)将特异性条带克隆测序后发现,mRNA、假设蛋白、表达蛋白、用于编码假定蛋白的mRNA序列V型质子ATP酶亚组、叶绿体中光合体系II CP47基因、叶绿体DNA、rRNA重复单元、核糖体蛋白等多种序列均存在甲基化修饰现象。这些特异序列可为我们寻找镉胁迫的生物标记物及胁迫响应的机理研究提供一定的依据。The DNA methylation is an important component of epigenetics and plays a significant role in the environmental stress-response. In this study, the effect of Cd2+on the methylation in genome-wide DNA of Arabidopsis was researched under Cd stress of 0~5.0 mg·L-1 Cd2+using methylation-sensitive amplified polymorphism(MSAP)technique. Root growth was significantly inhibited by Cd after 19 days of incubation. However, no obvious differences were observed in leaf numbers and fresh weight among all treatments. The percentages of MSAP in Arabidopsis treated with Cd2+were higher than that of the control(35%). Increasing Cd concentrations decreased the methylated(M)-type bands, but increased demethylated(D)-type bands. Variations in the brightness intensity of these two bands were observed. After the specific bands were cloned and sequenced, the methylation modification phenomena were found in multiple sequences such as mRNA, hypothetical protein, express protein, V-type proton ATPase enzyme subgroup, chloroplast photosystem II CP47 genes, Chloroplast DNA, rRNA repeat unit and ribosomal protein. These specific sequences could provide bases for the biomarkers of cadmium stress and stress-response mechanisms.

关 键 词：拟南芥 基因组甲基化 镉胁迫 MSAP 

分 类 号：Q943.2[生物学—植物学]