Non-symbiotic hemoglobin and nitrate reductase constitute an alternative to fermentation in waterlogging tolerance of mung bean [Vigna Radiata (L.) Wilczek]
Abstract
The objective of this study was to examine the role of nitrate reductase, nitric oxide and nonsymbiotic hemoglobin in imparting waterlogging tolerance in mung bean genotypes. Experiment was conducted with five cultivated mung bean [Vigna radiata (L.) Wilczek] genotypes viz., T 44, MH 96-1 (relatively tolerant), and Pusa Baisakhi, MH 1K-24 and PS 10 (susceptible) under pot-culture condition. Waterlogging induced reduction in relative water content, chlorophyll content and membrane stability index was comparatively less in tolerant genotypes T 44, MH 96-1 than in Pusa Baisakhi, MH 1K-24 and PS 10. The nitric oxide (NO) production activity increased up to 6 days of waterlogging treatment in all the genotypes, however T 44, MH 96-1 maintained more than double NO content than Pusa Baisakhi, MH 1K-24 and PS 10. Increase in nitrate reductase (NR) activity under waterlogging was observed up to 6-days of treatment in all the genotypes, and T 44, MH 96-1 maintained significantly higher NR activity than Pusa Baisakhi, MH 1K-24 and PS 10. Non-symbiotic hemoglobin (NSHb) and cNR mRNA expressions were studied only in the roots of control and waterlogging treated plants of T 44, MH 96-1, and PS 10. Waterlogging induced increase in expression was observed only in tolerant genotypes T 44 and MH 96-1, while little expression was observed in PS 10. In this study we have reported the involvement of non-symbiotic hemoglobin-nitric oxide homeostasis in the waterlogging tolerance of mung bean.
Keywords
Nitric oxide, non-symbiotic-hemoglobin, Vigna radiata, waterlogging
