Study on phenolics biosynthesis specific genes in orchids an integrated molecular and phytochemical approach

Abstract

Orchids, a diverse family of angiosperms, are renowned for their attractive flowers and medicinal properties. Due to their endangered status, consorted strategies for their conservation and sustainable utilization are required. The present study is on elucidating the phenolics biosynthesis pathway by focussing on enhanced biomass for upscaling, phytochemical profiling, evaluation of biological activity, and the regulatory role of pivotal genes. For the purpose, asymbiotic seed germination was attempted in two medicinal orchids, Cymbidium aloifolium and Vanda testacea. Phytochemical profiling was done in Cymbidium aloifolium using in vivo and in vitro sourced plants. Theacetone extracts from in vivo sourced plants exhibited higher phenolic and flavonoid content leading to significant antioxidant activity and cytotoxicity against human breast cancer cells. Additionally, a comprehensive in silico study including conserved domains and motifs analysis, multiple sequence alignment, physicochemical characterization, phylogenetic analysis, secondary and tertiary structure prediction, was carried out in pivotal genes of the phenolics biosynthetic pathway, like Phenylalanine Ammonia Lyase (PAL), Cinnamate 4-hydroxylase (C4H), 4-Coumarate:CoA-ligase (4CL), and type III Polyketide Synthase (PKS) in several orchid species. Expression profiling and cis-regulatory element analysis of these genes indicated variable expression in different tissues. Chalcone synthase (CHS), a type III PKS gene was cloned from both Cymbidium aloifolium and Vanda testacea and semi-quantitative expression analysis was done. This research identifies key genes for phenolics biosynthesis, setting the groundwork for future functional studies to enhance the production of phenolics in orchids. newline