Secondary metabolites and phenylpropanoid pathway enzymes as influenced under supplemental ultraviolet-B radiation in Withania somnifera Dunal, an indigenous medicinal plant

作者：Takshak Swabha; Agrawal S B^*

来源：Journal of Photochemistry and Photobiology B: Biology , 2014, 140: 332-343.

DOI：10.1016/j.jphotobiol.2014.08.011

• Phenylpropanoid pathway enzymes
• Secondary metabolites
• s-UV-B
• Withania somnifera

The present study aims to investigate the effects of supplemental ultraviolet B (3.6 kJ m(-2) day(-1) above ambient) radiation on secondary metabolites and phenylpropanoid pathway enzymes of Withania somnifera under field conditions at 40, 70, and 100 days after transplantation. Secondary metabolites%26apos; (alkaloids, anthocyanins, carotenoids, flavonoids, lignin, phytosterols, saponins, and tannins) concentrations were analysed at the end of the treatments. Activities of phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), 4-coumarate-CoA ligase (4CL), chalcone-flavanone isomerase (CHI), and dihydroflavonol reductase (DFR) were also determined. In treated plants, secondary metabolite-concentrations generally increased (higher concentrations being recorded in roots compared to leaves). Anomalies were recorded for lycopene in roots and phytosterols in leaves (all sampling ages); (beta-carotene declined in leaves at third sampling age. s-UV-B-treated plants depicted decrease in withanolide A content with concomitant increase in withaferin A (two major alkaloids analysed by HPLC) compared to their respective controls. Phenylpropanoid pathway enzyme-activities increased in leaves and roots under s-UV-B treatment, the latter showing greater increase. The study concludes that s-UV-B is a potent factor in increasing the concentrations of secondary metabolites and their biosynthetic pathway enzymes in W somnifera.

• 出版日期2014-11