Growth, phytochemical and gene expression changes related to the secondary metabolite synthesis of Solanum viarum Dunal

Abstract

Solanum viarum Dunal, is an important medicinal plant widely used as a source of raw material for the steroidal drug industry. Out of various steroidal precursors, solasodine, an analogue of diosgenin is the most important source of raw material for the synthesis of steroidal drugs. In the present study, growth and phytochemical variations in different tissue (leaves, stem, roots, and berries) of two contrasting genotypes, prickled and prickleless Solanum viarum were evaluated under in vitro and field conditions. Significant variation in growth, yield and contents of glycoalkaloids, phenolics, and flavonoids were evident between two genotypes under in vitro and field conditions. Prickleless genotypes showed improved growth parameters both under in vitro and field conditions, that helps in contributing to higher yield over prickled plants. Tissue-specific chemical analysis revealed that the leaves and roots of prickleless plants serve as a better repertoire for bioactive phytomolecules. The vegetative parts of in vitro grown 50 days old prickleless plants showed comparable/higher metabolite content than 7–8 month old field-grown plants. Hence it can be used as an alternative production platform for further upscaling, elicitation, and precursor feeding targets that enhances its commercial utility. The expression analysis of seven genes involved in the regulation of important metabolite biosynthesis in both prickled and prickleless genotype of Solanum viarum was also examined. The diverse metabolite profiles are correlated with variations in gene expression profiles. This study provides information about the key metabolites and its biosynthetic pathway genes, which could be useful for the selection of an improved prickleless genotype (“Nishkantak”) of Solanum viarum.