Efficient enhancement of capsaicinoids biosynthesis in cell suspension cultures of Capsicum chinense Jacq. cv. 'Umorok' by elicitors and differential gene expression analysis of elicited cultures

Capsaicinoids are responsible for pungency in chillies and have multiple health benefits and industrial applications. In vitro cell cultures of Capsicum with high capsaicinoids content may have the potential to serve as an alternative source for production of capsaicinoids. The present study investigated the effects of various elicitors, precursors and intermediates on the production of capsaicinoids in cell suspension cultures established from callus derived from the placental tissue explants of the highly pungent chilli cultivar, Capsicum chinense Jacq. cv. 'Umorok'. The study also, for the first time, reports the effect of elicitors on expression patterns of capsaicinoids biosynthesis genes in cell suspension cultures of C. chinense by quantitative real-time PCR. The maximum capsaicinoids content was obtained in cells elicitated with chitosan with average capsaicin and dihydrocapsaicin contents of 2.87 mg g(-1) fresh weight (FW) and 1.03 mg g(-1) FW, respectively. The expressions of the studied candidate genes were significantly up-regulated in response to elicitation. Enhancement of capsaicinoids biosynthesis by elicitation with chitosan was found to be associated with the up-regulation of the expression of all the studied candidate genes. The present study shows the association of different enhancement potential of different elicitors with differential expression pattern of the candidate genes of capsaicinoids biosynthesis pathways in cell suspension cultures of C. chinense and the information provided may help in understanding the key mechanism for enhancement of capsaicinoids biosynthesis by elicitation.