NMR-Based Metabolomic Profiling of Mungbean Infected with Mungbean Yellow Mosaic India Virus.

Mungbean is an important legume mainly cultivated in Southeast Asia known for cheap source of food protein. Yellow mosaic disease (YMD) of mungbean is one of the most damaging diseases caused by mungbean yellow mosaic virus (MYMV) and mungbean yellow mosaic India virus (MYMIV) in India. The genetic basis of YMD resistance of mungbean is not well studied yet. Our present studies aimed to explore the genetic basis of YMD resistance through molecular, biochemical and metabolomics approach. Molecular analysis of YMV-infected mungbean plant materials revealed the presence of MYMIV. Chlorophyll contents were estimated as mosaic symptoms that cause chlorosis and necrosis in infected leaves. Chlorophyll a, b and total chlorophyll content were significantly reduced by 27-55% in infected samples compared non-infected control samples. 1H NMR-based metabolomic profiling of virus-infected mungbean were carried out, and we found that vital changes occurred during the development of MYMIV infection in mungbean. A total of fifty metabolites were identified in mungbean leaf samples. Principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) separated the severely infected sample from the non-infected samples. Orthogonal partial least discrimination analysis (OPLS-DA) revealed significant differences in MYMIV-infected and non-infected control samples. The featured metabolites in MYMIV infected and control samples were amino acids, carbohydrates, and organic acids. Relative abundance of sucrose, γ-amino butyric acid (GABA), proline, alanine, phenylalanine, tryptophan, pyruvate, ascorbate, and citrates were found as differential metabolites. Our results suggest that metabolic changes in infected mungbean samples is related to the viral acquisition. The present study may help in better understanding the metabolic alterations during biotic stress in mungbean.