大叶秦艽中环烯醚萜积累与基因表达的相关性研究

Correlation study between accumulation of iridoids and expression of relative genes in Gentiana macrophylla

探讨陕西大叶秦艽中环烯醚萜积累和关键酶基因表达的相关性,采用超高效液相色谱-四级杆-静电场轨道阱高分辨质谱仪(UPLC-Q-Exactive MS)分析了环烯醚萜的含量,运用实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)测定环烯醚萜生物合成途径中关键酶基因的表达水平,SPSS计算相关性。结果表明,大部分环烯醚萜在根中含量最高,11-O-β-吡喃葡萄糖马钱苷酸酯在叶中含量最高,断氧化马钱苷酸在花中含量最高。14个酶基因在花部位表达高于其他部位,马钱苷酸O-甲基转移酶(loganate O-methyltransferase,LAMT)在叶中的表达量最高,香叶醇8-羟化酶(genraniol 8-hydroxylase,G8O)在根中表达量最高。相关性分析表明,7-去氧马钱苷元葡萄糖基转移酶(7-deoxyloganetic acid glucosyltransferase,7-DLGT)、异戊烯基焦磷酸异构酶(isopentenyl-diphosphate delta-isomerase,IDI)、裂环马钱苷合成酶(secologanin synthase,SLS)、甲羟戊酸二磷酸脱羧酶(mevalonate pyrophosphate decarboxylase,MVD)、7-去氧马钱苷酸7-羟化酶(7-deoxyloganic acid 7-hydroxylase,7-DLH)基因与环烯醚萜的含量呈高度正相关。关键酶基因表达在环烯醚萜的合成中发挥重要作用,是环烯醚萜积累调控的基础,是道地陕西秦艽质量形成机制的重要组成部分。

To research the correlation between the accumulation of iridoids and expression of key enzymes genes of Gentiana macrophylla,UPLC-Q-Exactive MS was used to detect iridoids content,and then quantitative real-time PCR(qRT-PCR)was used to analyze the expression of key enzyme genes in iridoids biosynthesis.Correlation was calculated by SPSS.The results showed that most iridoids were mainly distributed in roots,while loganic acid 11-O-β-glucopyranosyl ester was distributed in leaves and secologanoside was distributed in flowers.The expression of genes was higher in flower parts than in other parts,the expression of loganate O-methyltransferase(LAMT)was the highest in leaves and the expression of genraniol 8-hydroxylase(G 8 O)was the highest in roots.Correlation analysis showed that the relative expression of 7-deoxyloganetic acid glucosyltransferase(7-DLGT),isopentenyl-diphosphate delta-isomerase(IDI),secologanin synthase(SLS),mevalonate pyrophosphate decarboxylase(MVD)and 7-deoxyloganic acid 7-hydroxylase(7-DLH)genes were positively correlated with the contents of iridoids.The expression of the key enzyme genes play an important role in the synthesis of iridoids,which lay a foundation for the regulation of the accumulation of iridoids,and is also an important part of the mechanism of quality formation in the G.macrophylla.