铅胁迫下萝卜基因组DNA甲基化分析  

Analysis of Genomic DNA Methylation Level in Radish Under Lead Stress

作　　者：何玲莉[1] 沈虹[1] 王燕[1] 王娟娟[2] 龚义勤[1] 徐良[1] 柳李旺[1] 

机构地区：[1]南京农业大学园艺学院/作物遗传与种质创新国家重点实验室,江苏南京210095 [2]全国农业技术推广服务中心,北京100125

出　　处：《核农学报》2015年第7期1278-1284,共7页Journal of Nuclear Agricultural Sciences

基　　金：国家自然科学基金项目(31372064);江苏省自然科学基金(BK20140706);中央高校基本科研业务费专项资金项目(KYZ201209)

摘　　要：利用甲基化敏感扩增多态性(MSAP)技术,分析不同浓度铅(Pb)处理下萝卜基因组DNA甲基化水平的变化,探讨DNA甲基化在植株对Pb胁迫反应中的作用。结果表明,经100、400和800 mg·L-1Pb(NO3)2处理后,MSAP比率分别为12.7%、14.2%和17.0%,均高于对照;全甲基化率分别为9.7%、10.2%和12.8%,而其对照为9.5%,表明重金属铅胁迫后,某些位点发生了重新甲基化。萝卜肉质根中总甲基化水平随Pb处理浓度上升而提高。甲基化变异可分为重新甲基化、去甲基化、不定类型以及与对照相同等甲基化类型。萝卜Pb胁迫处理引起的植株基因组甲基化程度的提高主要是重新甲基化。研究为从DNA水平揭示重金属Pb毒害机理及植物对Pb胁迫的响应机制提供了理论依据。In this study, to explore the relationship between DNA methylation and Pb stress response, the DNA methylation level variations of radish plant in response to Pb stress were investigated. The MSAP ratio in radish seedlings exposed to lead at the concentration of 100,400and 800 mg＇L-1 was 12.7% , 14.2% and 17.0% , respectively, which was higher than that in the control. The full methylation levels （CmCGG in double strands） were 9.7% , 10.2% and 12.8% respectively, while the control was 9.5%. The level of increasing in MSAP and full methylation indicated that de novo methylation occurred in some 5＇-CCGG sites under Pb stress. The total DNA methylation level increased with raising of Pb concentration. Four types of MSAP patterns including de novo methylation, de-methylation, atypical pattern and no changes of methylation pattern were identified among Pb treatments and the control. DNA methylation alteration in radish plants treated with Ph was mainly through de novo methylation. These results provided the theoretical foundation for dissecting the molecular mechanism underlying Pb toxicant and plant response to heavy metal stresses.

关 键 词：萝卜 铅胁迫 DNA甲基化 甲基化敏感扩增多态性 

分 类 号：S631.1[农业科学—蔬菜学]