5-azaC对小麦幼苗生长及盐胁迫后DNA甲基化变异的影响  

Effects of 5-azaC on Wheat Seedling Growth and DNA Methylation Variation after Salt Stress

作　　者：李有芳 靖建国 郭翔 俞蓉 李召锋[1] 李卫华[1,2] LI Youfang;JING Jianguo;GUO Xiang;YU Rong;LI Zhaofeng;LI Weihua(College of Agriculture, Shihezi University, Shihezi, Xinjiang 832003, China;Key Laboratory of Oasis Ecological Agriculture,Xinjiang Production and Construction Crop,Shihezi,Xinjiang 832003,China)

机构地区：[1]石河子大学农学院,新疆石河子832003 [2]新疆生产建设兵团绿洲生态农业重点实验室,新疆石河子832003

出　　处：《西北植物学报》2020年第4期572-580,共9页Acta Botanica Boreali-Occidentalia Sinica

基　　金：新疆生产建设兵团科技局重点科技项目(2016AC027)。

摘　　要：DNA甲基化是调节植物生长发育,调控逆境基因表达的表观遗传机制之一。该研究采用不同浓度的DNA甲基化抑制剂5-azaC处理耐盐性不同的春小麦种子,分析其对种子萌发及盐胁迫后叶片基因组DNA甲基化的影响,探究DNA甲基化与小麦耐盐性之间的相关性。结果表明:(1)5-azaC显著抑制幼苗根长伸长,降低根系鲜重和干重。(2)甲基化敏感扩增多态性(MSAP)分析发现,单独盐胁迫后甲基化水平上升,5-azaC预处理材料经盐胁迫后甲基化水平呈下降趋势。(3)盐胁迫后基因组同时发生DNA去甲基化和DNA甲基化。敏盐品种‘新春6号’DNA去甲基化比率上升,DNA甲基化增加的比率下降;耐盐品种‘新春11号’DNA去甲基化比率和DNA甲基化增加的比率均上升,但去甲基化比率大于DNA甲基化增加的比率,说明盐胁迫引起的基因组DNA去甲基化为主,5-azaC预处理提高了盐胁迫下DNA去甲基化的比率。(4)DNA甲基化修饰位点序列分析发现,在核糖体亚基蛋白、蛋白激酶和转座子序列均存在DNA甲基化修饰现象,说明存在多种代谢途径共同参与了盐胁迫调控。DNA methylation is one of the epigenetic mechanisms that regulate plant growth,development and stress gene expression.In this study,we used 5-azaC,a DNA methylation inhibitor with different concentrations,to treat spring wheat seeds with different salt treatments.We analyzed the effects of 5-azaC on seed germination and DNA methylation changes after salt stress to explore the correlation between DNA methylation and salt tolerance of wheat.The results showed that:(1)5-azaC can significantly inhibit root length and reduce fresh weight and dry weight.(2)MSAP analysis showed that the methylation levels increased after salt stress alone,but the methylation level of 5-azaC pretreated materials after salt stress showed a downward trend.(3)After salt stress,DNA demethylation and DNA methylation occurred simultaneously in the genome.The rate of DNA demethylation increased for salt-sensitive cultivar‘Xinchun 6’,while the DNA methylation rate decreased.Both rates of DNA demethylation and DNA methylation increased for salt-tolerant cultivar‘Xinchun 11’,but the rate of demethylation was higher than that of DNA methylation.The results showed that the main change of DNA methylation in wheat leaves was DNA demethylation after salt stress.5-azaC increased the rate of DNA demethylation under salt stress.(4)Sequence analysis of DNA methylation modification sites found that DNA methylation modifications were present in ribosomal subunit proteins,protein kinases,and transposon sequences,indicating that salt stress could be resisted by multiple metabolic pathways.

关 键 词：小麦 盐胁迫 5-氮杂胞苷(甲基化抑制剂) 幼苗生长 DNA甲基化 

分 类 号：Q789[生物学—分子生物学] S512.1[农业科学—作物学]