Role of glutathione in methylglyoxal detoxification pathway during yellow mosaic virus (YMV) infection in black gram (Vigna mungo (L.) Hepper)

Abstract

Yellow mosaic virus (YMV) infection occurred through whitefly (Bemisia tabaci) transmitted begomovirus in black gram during kharif season but the crop did not show any signs of infection during the spring season. To compare and comprehend the intricate link between the glutathione molecule and methylglyoxal detoxification pathway, three black gram cultivars-cv.KUG253 (highly susceptible to YMV), MASH114 (resistant) and cross (cv. KUG253 × MASH114) were sown during kharif and spring season. YMV brutally infected the leaves of cv.KUG253 in the kharif season at 20 days after sowing (DAS) and caused severe chlorosis by 40 DAS which made the leaves papery and feeble. On the contrary, YMV infection was completely absent in the other two cultivars of the black gram and during the spring season, all three cultivars exhibited normal growth without any sign of this disease. The main cytotoxic product formed under YMV infection was methylglyoxal, as significantly higher specific activity was observed for methylglyoxal reductase (MGR) and glyoxalase enzymes in the kharif season rather than spring season in all the three cultivars. Glyoxalase III has been recently discovered for the detoxification of MG and is independent of the glutathione molecule, but no report has been published till now which elaborately explains its role during the pathogenic attack on the plants.