盐胁迫诱导玉米苗期DNA甲基化变异的研究

为研究不同浓度盐处理下玉米叶片DNA甲基化情况,以耐盐玉米自交系黑玉米为材料,利用甲基化敏感扩增多态性(MSAP)技术,分析不同盐浓度胁迫7 d后,玉米苗期叶片胞嘧啶甲基化水平和模式的变化。结果表明,经0(CK)、50、100、150、200、250 mmol·L~(-1)NaCl处理后,基因组DNA甲基化比率分别为52.79%、57.47%、51.98%、47.39%、49.16%、47.06%,其中只有50 mmol·L~(-1)NaCl处理高于CK,其他处理呈降低趋势,去甲基化变化幅度相对较大(1.8%~12.2%);回收差异片段后测序并对序列进行同源比对,结果发现16个甲基化位点涉及植物生长发育的多个基因。本研究结果为玉米耐盐机理的深入研究提供了一定的依据。

Analysis of the DNA Methylation of Maize in Response to Salt Stress

To determine the changes of DNA methylation under different concentrations of salt stress,the leaves of maize at the seedling stage were used to estimate the levels and patterns of cytosine methylation by methylation sensitive amplified polymorphism (MSAP) method.The results showed that the DNA methylation ratio is 52.79％,57.47％,51.98％,47.39％,49.16％,47.06％ under 0 (control),50,100,150,200,250 mmol·L-1 NaCl stress,respectively.However,only 50 mmol· L-1 NaCl treatment showed higher DNA methylation ratio than in the control,and at other concentrations,the DNA methylation ratios were declining as concentrations increased but lower than control,which indicate that the de-methylation might play a significant role in salt stress (1.8％ to 12.2％).In addition,sequencing and blast results showed that a total of 16 methylation sites were detected,which may relate to many genes of plant growth and development.These experimental results provided a theoretical basis for further study on the salt resistant mechanism of maize.