Physio-biochemical and nutritional alterations in faba bean due to bean yellow mosaic virus infection

The association of bean yellow mosaic potyvirus (BYMV) was investigated earlier with the severe mosaic and stunting disease of V. faba. In the present study, we mechanically transmitted BYMV on V. faba to assess the impact on physiological, biochemical, and nutritional attributes. BYMV-inoculated plants exhibited severe symptoms, and their height, length of the pod, and seed yield (size and number) were reduced to half of the mock-inoculated V. faba. In BYMV-inoculated V. faba, chlorophyll a, b, and total (Chl a + Chl b) were lowered to 66.70%, 64.94%, and 66.19% respectively, and corroborated with the decrease in photosynthetic efficiency (Fv/Fm) from 0.36 to 0.26. An increase in membrane ion leakage and malondialdehyde was observed in inoculated V. faba indicating virus-induced physiological stress. The non-structural carbohydrates, total protein, and free proline contents were also significantly altered. More, the high accumulation of salicylic acid and other defense-related antioxidant enzymes (ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase, and catalase) was observed to ameliorate virus-induced stress. An increase in polyphenols and flavonoids: gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, rutin, ferulic acid, quercetin, and kaempferol suggests the proactive action by BYMV-infected V. faba. A reduced accumulation of nutrition-related parameters while induced accumulation of anti-nutritional factors like tannin (as tannic acid) and phytate observed is suggestive of poor nutritional quality of the plants. The present study comprehensively elucidates the BYMV-induced perturbations in physio-biochemical and nutritional attributes of V. faba, diminishing the quality of plants and seeds, and raises serious concerns for the management measures against the BYMV.