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

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.