NADPH oxidase as the source of ROS produced under waterlogging in roots of mung bean

Abstract

The objective of this study was to examine the role of NADPH oxidase on superoxide radical production under waterlogging in mung bean (Vigna radiata) cvs. T 44 (tolerant) and Pusa Baisakhi (PB) (susceptible), and wild species Vigna luteola. Two days of waterlogging caused decline in superoxide radical (O 2˙⎯ ) contents in all the genotypes, however, further waterlogging up to 8 d caused significant increase in O 2˙⎯ contents. In control and revived plants O 2˙⎯ contents were higher in PB, while under waterlogging stress T 44 and V. luteola showed greater increases in the O 2˙⎯ contents. During waterlogging the increase in O 2˙⎯ content was found to be due to the diphenylene iodonium chloridesensitive NADPH oxidase (NOX). This was further confirmed by the waterlogging induced increase in NOX activity, which was higher in tolerant genotypes T 44 and V. luteola compared with PB. Gene expression studies showed enhanced expression of NOX in the roots of waterlogged V. luteola and T 44, while little expression was observed in control or treated plants of PB. PCR band products were cloned and sequenced, and partial cDNAs of NOX was obtained. Results suggest that increase in O 2˙⎯ content during waterlogging could be due to the induction of membrane linked NOX.

Global regulation of reactive oxygen species scavenging genes in alfalfa root and shoot under gradual drought stress and recovery

“…NADPH oxidase is involved in various plant biotic and abiotic stress responses. 9,[18][19][20] The expression of most NADPH oxidases increased in both roots and shoots of alfalfa under drought, especially under severe drought stress (D11; Fig. 1).…”

Exogenous salicylic acid ameliorates waterlogging stress damages and improves photosynthetic efficiency and antioxidative defense system in waxy corn

“…When plants were exposed to waterlogging stress, ROS was overproduced and accumulated, further leading to the generation of oxidative stress (Sairam et al 2011, Patel et al 2019. Plants minimize oxidative stress by activating an enzymatic antioxidant defense system, such as SOD, CAT, and POD, to scavenge ROS.…”

Physiological and Molecular Mechanisms of Flooding Tolerance in Plants

“…Accumulation of hydrogen peroxide (H 2 O 2 ) was induced in hypoxia-stressed barley and wheat seedlings (Biemelt et al 2000 ;Kalashnikov et al 1994 ). Signifi cant increase in lipid peroxidation, superoxide radical production, and membrane injury was observed in waterlogging-stressed, maize, pigeon pea, and mung bean genotypes (Yan et al 1996 ;Kumutha et al 2009 ;Sairam et al 2011a ). ROS production under soil fl ooding is owing to the induction of membrane bound NADPH oxidase, as indicated by inhibitor and gene expression studies in pigeon pea (Kumutha et al 2009 ).…”