聚乙二醇(PEG)胁迫诱导水稻DNA甲基化变异与脯氨酸代谢相关性研究  

The research on correlation between DNA methylation variation and proline metabolism induced by PEG stress in rice

作　　者：张春玉[1,2] 

机构地区：[1]长春职业技术学院食品与生物技术分院,吉林长春130033 [2]东北师范大学生命科学学院,吉林长春130024

出　　处：《东北师大学报（自然科学版）》2015年第2期108-114,共7页Journal of Northeast Normal University(Natural Science Edition)

基　　金：国家重点基础研究发展计划(973计划)项目(2011CB100205);吉林省科技发展计划项目(201205048)

摘　　要：干旱胁迫经常伴随着植物脯氨酸代谢的变化.为了研究干旱胁迫条件下脯氨酸的累积与DNA甲基化变异之间的相关性,采用聚乙二醇(PEG)模拟天然的干旱胁迫条件,以15%聚乙二醇(PEG)胁迫处理的水稻幼苗为实验材料,利用DNA甲基化敏感扩增多态性技术(MSAP)筛选出1株甲基化变异最大的单株(S0);采用Southern印迹杂交(Southern blot)和实时荧光定量聚合酶链式反应(Realtime-PCR)分别检测S0和S1代(S0自交产生的后代)与脯氨酸代谢相关基因的DNA甲基化变异和基因表达的变化情况,并测定了S0和S1代叶片游离脯氨酸的含量.结果表明:S0代谷氨酸合成途径的相关基因没有发生甲基化,S1代谷氨酸合成途径的Δ1-吡咯啉-5-羧酸合成酶(P5CS)基因在后代(14个单株)全部发生了CHG去甲基化变异,变异率为100%.鸟氨酸合成途径的鸟氨酸转氨酶(δ-OAT)基因在后代中有3个单株发生了去甲基化变异,变异率为21%;Δ1-吡咯琳-5-羧酸脱氢酶(P5CDH)和Δ1-吡咯啉-5-羧酸还原酶(P5CR)基因的甲基化没有明显变异,变异率为0.Realtime-PCR结果表明:S1代P5CS基因表达上调率为100%;δ-OAT和P5CR基因S1代14个单株中有10个单株的表达发生了上调,上调率为71.4%;降解途径中的关键基因P5CDH基因S1代表达下调率7.1%.研究结果表明DNA甲基化变异与基因表达之间可能仅在部分基因上存在一定的关联性.Drought stress is often accompanied the changes of proline metabolism in plant. To study the correlation between DNA methylation and accumulation of proline under drought stress,subjected rice （Oryza sativa L. ）to a stress of 15% PEG treatment for four consecutive days, selected on a random basis 14 treated rice plants and performed methylation-senstive amplified polymorphism （MSAP） analysis,and identified one individual that showed clear changes in DNA methylation. Discussed the correlation between DNA methylation variations and gene expression in So and S1 by methylationsensitive Southern blot analysis and Real-time-PCR. And meanwhile,detected the content of proline in S0 and S1. Southern blot indicated that no obvious alteration in DNA methylation were detected in So, and a key gene in the glutamate pathway of proline biosynthesis, PSCS, exhibited markedly demethylation at CHG sites in all 14 selfed progenies of S1 ,the variation ratio was 100% ,another key gene in the ornithine pathway,3-OAT, showed demethylation at CHG sites in three of the 14 selfed progenies,the variation ratio was about 21%. In contrast,two genes,P5CDH and P5CR,did not show changes in DNA methylation. Although P5CDH showed no obvious alteration in DNA methylation, the variation ratio was 0. Realtime-PCR indicated that up-regulation ratio of P5CS was 100K, up- regulation ratio of 3-OAT and PSCR was 71.4% ,down-regulation ratio of PSCDH was 7.1% in leaf tissue of selfed progenies, which suggested that DNA methylation and proline biosynthesis were probably related only in some of the genes.

关 键 词：水稻 聚乙二醇(PEG) 脯氨酸代谢 DNA甲基化 

分 类 号：Q943.2[生物学—植物学]