Chapter 8 - Nitric oxide and hydrogen sulfide interactions in plants under adverse environmental conditions

Abstract

The inherent defense system of plants ascertains their survival under any adverse environmental condition. However, perception of stress stimulus and accurate response of defense mechanism to the perceived stimulus before the onset of stress-induced damage is vital for the endurance of plants under stressful conditions. The functioning of the defense system is operated by a complex signaling network, operated by the synchronization of various signaling molecules. Of these, hydrogen sulfide (H2S) and nitric oxide (NO) have been shown to play a substantial role in the protection of plants against various abiotic stresses such as salinity, drought, extreme temperature, metal stress, UV radiation, etc. The action of H2S and NO involves several other signaling molecules, phytohormones, and nutrients. Protection of plants against abiotic stress-induced impairments by H2S and NO is carried out by activating antioxidant defense system, accumulation of osmolytes, and regulation of the expression of various genes and proteins. However, the molecular mechanism by which H2S and NO exert their effect in modulating defense system operates through posttranslational modifications (PTMs) of proteins. As a result of PTM, the targeted proteins exhibit alteration in their stability, biochemical activity, conformation, subcellular localization, and protein–protein interaction that may lead to the upregulation or downregulation of the activity of the proteins. The present chapter highlights recent advances in H2S and NO research in relation to their role in plant adaption to abiotic stresses.