Identification and characterization of potential sources of waterlogging tolerance in Vigna species as revealed by physiological, biochemical and gene expression profiling

Mungbean is an important short duration grain legume; consumed as food, feed and fodder. The 32 Vigna accessions including cultivated and wild belong to nine different species were evaluated in present study. Out of them, six genotypes namely PRR 2008-2, PRR 2008-2-sel, TCR-93, L-24, TCR-20 and W-17 were found tolerant to waterlogging (WL) had > 75.0% survival. These genotypes had strong root system, higher shoot elongation and delayed chlorophyll degradation. Two genotypes PRR 2008-2 and PRR 2008-2-sel showed induction of adventitious roots in the hypocotyl region under WL. TCR-93, L-24,TCR-20 and W-17 also showed similar mechanism but root induction was appeared later than PRR 2008-2 and PRR 2008-2-sel. In addition to root induction in hypocotyl region, these genotypes also showed the formation of aerenchyma as adoptive mechanism. The higher activity of ADH , proline and O 2 •− were recorded in PRR 2008-2 whereas, it was lower in IPM 02-3. Further, the differential expression of candidate genes and transcriptional factors like SOD, CAT, MAPK, WRKY, NAC and ARF provide a fundamental resource for understanding signaling behavior, hormonal regulation and antioxidant homeostatsis involved in WL tolerance.