Blackgram (Vigna mungo L. Hepper) production is hindered by mungbean yellow mosaic virus (MYMV) with disease incidence up to 85% in hot spot locations of Tamil Nadu, India. Field screening of 50 genotypes identified Mash 114 as resistant and CO 5 as susceptible cultivars. To understand the resistance mechanism, temporal metabolome variations of resistant (RC) and susceptible (SC) cultivars were assessed at 3, 6, and 12 days post-inoculation with MYMV via whitefly transmission using GC-MS. The study included aviruliferous whitefly and healthy controls. Data analysis identified 98 differential compounds across various metabolic groups. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed distinct metabolic profiles, with RC accumulating antiviral terpenoids such as ursolic acid, betulin, and umbelliprenin, while SC upregulated lipids and fatty acids favoring virus replication. These findings provide insights for breeders to identify resistant sources and pave the way for improved MYMV management strategies using antiviral products.
Keywords: GCMS; MYMV; blackgram; terpenoids; ursolic acid (UA).