Influence of elicitors on effective constituents and expression of key metabolic enzyme genes in hairy roots of Atropa belladonna / 中草药

ABSTRACT

Objective To improve the yield of the effective medicinal ingredients of Atropa belladonna, to provide economic and efficient method for the actual production of A. belladonna, therefore to provide a basic reference for the related research on the mechanism of secondary metabolism of medicinal plants. Methods In this study, the influences of four kinds of elicitors, including methyl jasmonate (MJ), AgNO3, salicylic acid (SA), yeast extract (YE), on the accumulation of active components and the expression level of key metabolic enzyme genes, including putrescine N-methyl transferase (pmt), tropinone reductase-I (trI), and hyoscyamine-6-β-hydroxylase (h6h), were studied in hairy roots of A. belladonna. 0.5 g fresh hairy roots of A. belladonna were cultivated in B5 liquid medium. 12 d later, these mediums were replaced with the new medium containing one kind of four elicitors. Hairy roots were taken samples after 2 d to mensurate the fresh weight, dry weight, the content of tropane alkaloids, some physiological indexes, and three key genes expression level. Results MJ inhibited the growth and tropane alkaloids accumulation of hairy roots. The gene expression level of pmt and trI also decreased compared with control group (CK). The contents of tropane alkaloids and the expression level of pmt, trI and h6h were all increased compared with CK by the treatment of AgNO3, while the growth of hairy rootswas inhibited; SA contributed to the increased content of hyoscyamine, but with no obvious influence on growth of hairy roots. As to YE, the content of tropane alkaloids and the expression level of pmt, trI, h6h were all increased correspondingly. Further more, YE was benefit for the growth of hairy roots. Conclusion Elicitors had selective influence on growth and tropane alkaloids accumulation in hairy roots of A. belladonna. The best elicitor on accumulation of tropane alkaloids was AgNO3. YE could effectively improve of the growth of hairy and contents of tropane alkaloids. This study concluded that these elicitors influence the secondary metabolism of A. belladonna by regulating and controlling the expression level of some genes of key metabolic Enzyme, which could provide an effective method to enhance the medicinal composition in the culture of hairy roots of A. belladonna.