水分胁迫下马铃薯基因组DNA甲基化水平变化分析

DNA甲基化是表观遗传学修饰的重要研究内容之一,在植物生长发育和响应逆境胁迫等过程中起重要作用,其中水分胁迫是对植物生长发育最具危害的逆境胁迫之一。为探索马铃薯DNA甲基化与水分胁迫之间的关系,本研究采用PEG-6000模拟水分胁迫处理两个马铃薯品种‘青薯9号’和‘大西洋’,在PEG0%(对照),5%和10%浓度下,利用MSAP技术检测‘青薯9号’和‘大西洋’甲基化水平变化情况。结果表明:在相同条件下,抗旱型品种‘青薯9号’甲基化水平高均于干旱敏感型品种‘大西洋’。在0%(对照)、5%和10%PEG胁迫下,‘青薯9号’MSAP比率为42.49%、38.14%、49.21%,甲基化水平与对照相比先降低后升高,‘大西洋’MSAP比率29.17%、22.92%、17.58%,甲基化水平逐渐降低。经统计,5%PEG和10%PEG胁迫下,‘青薯9号’和‘大西洋’均出现甲基化和去甲基化现象,其中‘青薯9号’甲基化和去甲基化比率分别为10.92%、6.43%和11.98%、15.36%,‘大西洋’分别为1.59%、8.22%和42.18%、24.34%,甲基化变异模式以去甲基化为主。‘青薯9号’和‘大西洋’均能发生CNG、CG和CG/CNG位点的甲基化和去甲基化,在水分胁迫下会产生较多的CNG和CG/CNG位点。本研究结果为探究马铃薯抗旱机制提供了理论基础。

Study on Changes of Genomic DNA Methylation Level in Potato under Drought Stress

DNA methylation is one of the important research contents of epigenetic modification.It plays an important role in the process of plant growth and development and response to stress.Among them,water stress is one of the most harmful stresses to plant growth and development.To explore the relationship between DNA methylation in potato and water stress,PEG-6000 was used to simulate the water stress treatment of two potato cultivars’Qingshu9’and’Atlantic’in this study.At 0%(control),5%,and 10%PEG concentrations,MSAP technology was used to detect’Qingshu9’and Changes in’Atlantic’methylation levels.The results showed that:Under the same conditions,the drought-resistant variety’Qingshu9’had higher methylation levels than the drought-sensitive variety’Atlantic’.With the increase of stress concentration,MSAP ratio of’Qingshu9’was 42.49%,38.14%,49.21%,and the overall trend of methylation level was increased,while the’Atlantic’MSAP ratio was 29.17%,22.92%,and17.58%,and the methylation level was gradually decreased.The methylation and demethylation ratios of’Qingshu9’treated with 5%and 10%PEG stress were 10.92%,6.43%,11.98%,and 15.36%,and the’Atlantic’was 1.59%,8.22%,and 42.18%,24.34%.There were methylation and demethylation in both’Qingshu9’and’Atlantic’,but demethylation was the main change trend.Methylation and demethylation of CNG,CG and CG/CNG sites can occur in both’Qingshu9’and’Atlantic’,and more CNG and CG/CNG sites can be generated under drought stress.