温度胁迫下泽泻中三萜类成分及其生物合成酶基因的相关性研究

Correlation Study Between the Expression of Triterpenoids and Biosynthesis Enzyme Genes in Alisma Orientale Under Temperature Stress

关键词:  泽泻  温度胁迫  三萜类成分  生物合成酶  相关性

Key words:  Alisma orientale  temperature stress  triterpenoids  biosynthetic genes  correlation

摘要:

目的 研究温度胁迫下泽泻中三萜类成分及其生物合成酶基因表达的相关性。方法 以不同温度（0，6，16，26℃）栽培下的泽泻为研究对象，采用UPLC-MS/MS检测泽泻叶片中8种三萜类成分泽泻醇A、泽泻醇B、泽泻醇F、泽泻醇G、24-乙酰泽泻醇A、23-乙酰泽泻醇B、23-乙酰泽泻醇C、24-乙酰泽泻醇F的含量及总量，并采用qRT-PCR技术检测三萜类合成途径中生物合酶HMGR、SQS、FPPS、MVD的mRNA水平。结果 泽泻叶片中23-乙酰泽泻醇B及8种三萜类成分总量与SQS、HMGR基因的mRNA水平呈正相关（P<0.05）；而FPPS及MVD基因在不同温度干预下mRNA水平无显著性变化。结论 SQS、HMGR可能是泽泻中三萜类成分合成的限速酶，且其表达受到环境温度的调节。

Abstract:

OBJECTIVE To explore the correlation between the expression of triterpenoids and biosynthetic enzyme genes in Alisma orientale under temperature stress. METHODS Alisma orientale under different temperature(0, 6, 16, 26℃) cultivations were used as test materials, the content of eight triterpenoids in leaves, including alisol A, alisol B, alisol F, alisol G, alisol A 24 acetate, alisol B 23 acetate, alisol C 23 acetate and alisol F 24 acetate, was detected by UPLC-MS/MS. And then the qRT-PCR was utilized to analyze the expression of biosynthetic enzyme genes HMGR, SQS, FPPS and MVD mRNA in triterpenoid synthesis pathway. RESULTS Alisol B 23 acetate and the total content of eight triterpenoids in leaves of Alisma orientale were positively correlated with the relative expression of SQS and HMGR mRNA, respectively(P<0.05). While, there was no significant difference in the expression of genes FPPS and MVD mRNA with different temperature interventions. CONCLUSION SQS and HMGR may be the rate-limiting enzymes in the synthesis of triterpenoids in Alisma orientale, and their expression is regulated by temperature.