地黄次生代谢产物生物合成基因表达水平与其含量的相关性分析

为了研究地黄次生代谢产物生物合成基因在不同地黄材料中的相对表达量，并分析其与次生代谢产物积累的关系，从地黄叶、地黄组培苗叶、地黄毛状根中提取总RNA，以地黄TIP41为内参基因，利用实时荧光定量PCR技术分析梓醇、毛蕊花糖苷生物合成相关酶基因的表达量，并分别采用高效液相色谱法测定3种材料中梓醇和毛蕊花糖苷的含量、紫外分光光度法测定总环烯醚萜苷的含量，再对两者进行相关性分析。结果表明，3种不同地黄材料中次生代谢产物的生物合成相关酶基因的表达量及其含量差异较大。经相关性分析，地黄中梓醇的含量与GGPPS2基因的表达量呈显著正相关，总环烯醚萜苷的含量与GGPPS1、G10H基因的表达量也有显著相关性，说明GGPPS2与梓醇的合成有关，GGPPS1、G10H与总环烯醚萜苷的合成有关；而毛蕊花糖苷的含量与ADT、ASP5、4CL、C3H、HCT、GOT2基因的表达量均没有显著相关性。上述结果为地黄次生代谢产物生物合成途径的相关研究提供了参考。

Correlation Analysis Between Expression Levels of Biosynthetic Genes for Secondary Metabolites and Their Contents in Rehmannia glutinosa

In order to study the relative expression of the biosynthetic genes for secondary metabolites in different materials of Rehmannia glutinosa, and analyze the relationship between gene expression and secondary metabolites accumulation, this paper extracted total RNA from leaves, leaves of tissue culture seeding and hairy roots of R. glutinosa, respectively. TIP41 was used as a reference gene, and the relative expression of the biosynthesis-related enzymes genes for catalpol and verbascoside were analyzed by real-time quantitative PCR. The content of catalpol and verbascoside in 3 kinds of material were measured by HPLC, respectively, while the content of total iridoid glycoside was measured by UV spectrophotometry, and then the correlation between their contents and relative expressions of the genes related to biosynthesis enzymes were analyzed. The results indicated that there were more differences in the expression levels of the genes related to biosynthesis enzyme for secondary metabolites and their contents among the 3 different kinds of R. glutinosa materials. According to relative correlation analysis, the content of catalpol was significantly and positively correlated with the expression quantity of GGPPS2, and the content of total iridoid glycoside was also significantly correlated with the expression quantities of GGPPS1 and G10H, indicating that GGPPS2 was related with the synthesis of catalpa, GGPPS1 and G10H might be related to total iridoid glycoside biosynthesis. While, there were no significant correlation between the content of verbascoside with the expression levels of ADT, ASP5, 4CL, C3H, HCT and GOT2. These results provided references for relative studies on secondary metabolites biosynthetic pathways of R. glutinosa.