Reducing the biosynthesis of condensed tannin in winged bean ( (L.) DC.) by virus-induced gene silencing of anthocyanidin synthase (ANS) gene.

Unlabelled: The Underutilized legume-winged bean ( (L.) DC.) and its various parts are infested with condensed tannin (CT) or proanthocyanidin (PA). CT has anti-nutritional effect as it adversely affects the digestion of proteins, minerals and vitamin among ruminants and humans. It is also responsible for low protein digestibility and decreased amino acid availability. One of the probable reasons of underutilization of is due to its infestation with CT. Histochemical staining of various tissues of with dimethylcinnmaldehyde (DMACA) developed a deep-blue colour indicating the presence of polyphenolic condensed tannin. Structural monomeric unit catechin and epi-catechin were reported to be responsible for biosynthesis of CT in . The enzyme anthocyanidin synthase (ANS) and its corresponding transcripts were identified and phylogenetically mapped. The transcript was subjected to virus-induced gene silencing (VIGS) through agro-infiltration in for reducing the CT-content. The WbANS-VIGS induced resulted in four-fold decrease of CT as compared to the control . A decrease of 73% of CT level was reported in VIGS silenced Wb-ANS line of . This study resulted and confirmed that, the silencing of (ANS) gene in has a regulatory effect on the condensed tannin biosynthesis. This study will pave way for further manipulation of ANS enzyme for reducing the biosynthesis of the anti-nutrient CT. Reducing the CT content will make this underutilized legume more acceptable.

Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03435-5.