Effects of Exogenous Nitric Oxide on Growth and Alkaloid Accumulation of Catharanthus roseus Seedlings under Light-Shading Treatment / 中国药学杂志

ABSTRACT

OBJECTIVE: To explore the molecular mechanism of no regulating alkaloid accumulation under light- shading stress. METHODS: The seedlings of Catharanthus roseus (C. roseus) were used as material, and the leaves were sampled 7 d later. Leaves growth morphology were studied, the contents of alkaloids and hormones were determined by HPLC and the genes expression were analyzed by fluorescence quantitative RT-PCR. RESULTS: Under compound treatment (T3), the growth index of leaves from C. roseus significantly increased, and the content of hormones and alkaloids increased significantly. The expression of Myc1 and key genes (G10h, Tdc, Sgd and Str) in the pathway were significantly up-regulated. Correlation analysis showed that the contents of 6-BA and ABA were positively correlated with Myc1 expression (P<0.01); Myc1 expression was positively correlated with the expression of Tdc, Str, Sgd, and Dat (P<0.01); there was a significant positive correlation between the genes expression and alkaloid content (P<0.01). CONCLUSION: The exogenous NO donors (SNP) could act as a signaling molecule and regulate the increase of hormones content under light-shading stress, increase the high expression of transcription factors Myc1, activate the expression of key genes in the metabolic pathway of alkaloids, and increase the content of vinblastine and vincristine in C. roseus.