Biotic elicitor-induced changes in growth, antioxidative defense, and metabolites in an improved prickleless Solanum viarum

Solanum viarum serves as a raw material for the steroidal drug industry due to its alkaloid and glycoalkaloid content. Elicitation is well-known for measuring the increase in the yield of bioactive compounds in in vitro cultures. The current study was performed for the accumulation of metabolites viz. solasodine, solanidine, and alpha-solanine in S. viarum culture using microbial-based elicitors added in 1%, 3%, 5%, and 7% on 25(th) and 35(th) day of culture period and harvested on 45(th) and 50(th) days of culture cycle. The treatment of 3% Trichoderma reesei and Bacillus tequilensis culture filtrate (CF) significantly increased biomass, alkaloids/glycoalkaloid content, and yield in S. viarum. T. reesei was found to be the best treatment for enhanced growth (GI = 11.65) and glycoalkaloid yield (2.54 mg DW plant(-1)) after the 50(th) day of the culture cycle when added on the 25(th) day. The abundance of gene transcripts involved in the biosynthesis of alkaloids/glycoalkaloids, revealed by quantitative real-time PCR expression analysis correlates with the accumulation of their respective metabolites in elicited plants. Biochemical analysis shows that elicited plants inhibited oxidative damage caused by reactive oxygen species by activating enzymes (superoxide dismutase and ascorbate peroxidase) as well as non-enzymatic antioxidant mechanisms (alkaloids, total phenols, total flavonoids, carotenoids, and proline). The findings of this study clearly demonstrate that the application of T. reesei and B. tequilensis CF at a specific dose and time significantly improve biomass as well as upregulates the metabolite biosynthetic pathway in an important medicinal plant- S. viarum.

Automated summary

This study aimed to enhance the production of alkaloids and glycoalkaloids in Solanum viarum culture by adding microbial-based elicitors. The results showed that the treatment with 3% Trichoderma reesei and Bacillus tequilensis culture filtrate significantly increased biomass and yield. Quantitative real-time PCR expression analysis revealed that the abundance of gene transcripts involved in metabolite biosynthesis correlated with their accumulation in elicited plants.