5-氮杂胞苷对醇型广藿香DNA甲基化及指标性成分的影响

Effects of 5-azacytidine on DNA methylation and index components in patchouliol-type Pogostemon cablin

该研究应用5-氮杂胞苷(5-azaC)处理醇型广藿香,高效液相色谱法(HPLC)评估分析广藿香DNA甲基化水平的变化,气质联用技术(GC-MS)检测广藿香中指标性成分的含量,传统方法观察和测量广藿香的农艺性状,探究广藿香中DNA甲基化与指标性成分含量和生长发育之间的关系。结果表明,5-azaC处理后,广藿香DNA甲基化水平显著降低,DNA甲基化水平随5-azaC浓度的增加而逐步降低;不同浓度5-azaC处理醇型广藿香30 d后发现百秋李醇的含量变化不大,50、100μmol·L^(-1)处理组的广藿香酮含量与对照组比较均有显著上升,100μmol·L^(-1)处理组广藿香酮与百秋李醇差值最大,其次为50μmol·L^(-1)处理组。解除抑制90 d后,处理组的广藿香酮含量显著增加,百秋李醇含量显著降低;广藿香酮含量升高的同时百秋李醇含量下降,二者的总和无显著性差异。5-azaC显著抑制广藿香的生长发育,抑制作用具有剂量累计效应。这些结果说明DNA甲基化在醇型广藿香指标性成分的生物合成和生长发育过程中发挥重要的调控作用,适当去甲基化可直接促进广藿香酮的合成,间接影响百秋李醇含量的积累。

This study aims to explore the relationship of DNA methylation with the contents of the index components as well as the growth and development of Pogostemon cablin. The demethylation reagent 5-azacytidine(5-azaC) was used to treat the tissue culture seedlings of patchouliol-type P. cablin. High performance liquid chromatography was employed to evaluate the changes of DNA methy-lation in P. cablin, and GC-MS to detect the contents of index components in P.cablin. The agronomic characters of P.cablin were measured using the common methods. The results showcased that DNA methylation of P.cablin was significantly reduced by 5-azaC in a concentration-dependent manner. Thirty days after treatment with 5-azaC at different concentrations, the content of patchouli alcohol changed slightly;compared with that in the control group, the content of pogostone in 50 μmol·L^(-1) and 100 μmol·L^(-1) 5-azaC groups was significantly up-regulated. The 100 μmol·L^(-1) 5-azaC group had the largest differences in contents of pogostone and patchouli alcohol compared with the control group, followed by the 50 μmol·L^(-1) 5-azaC group. Ninety days after disinhibition, the content of pogostone in the treatment group was significantly increased and the content of patchouli alcohol was significantly decreased. In addition, 5-azaC significantly inhibited the growth and development of P.cablin in a dose-dependent manner. These results indicate that DNA methylation regulates the biosynthesis of the index components in patchouliol-type P.cablin and proper demethylation can directly promote the synthesis of pogostone and indirectly affect the accumulation of patchouli alcohol.