Interaction of Nitric Oxide with Phytohormones under Drought Stress

Abstract

Plants are often exposed to a plethora of stress conditions such as salinity, extreme temperatures, drought, and heavy metals that can greatly impact farmer's income. Nitric oxide (NO) has been implicated in resistance to various plant stresses and hence gaining increasing attention from plant researchers. NO mediate various abiotic and biotic stresses in plants including drought stress. However, it is still unclear about the actual involvement of NO in drought stress responses at a whole plant level. Whether NO act alone or in coherence with other phytohormones and signaling molecules is an open question till now. Here we summarized the interaction of NO with the well-known phytohormones in coping with the drought stress.

Insights Into the Nitric Oxide Mediated Stress Tolerance in Plants

“…Although initial discoveries in plants recognized NO as an atmospheric toxic pollutant for plant foliage, it was eventually considered as a modulator of plant defense during pathogen attacks. The increasing number of reports demonstrated the role of NO in a plethora of plant development processes including seed germination (Arc et al, 2013), root formation, different stages of the seed development, gravitropism, stomatal movements, photosynthesis, mitochondrial functionality, senescence, plant maturation (Sun et al, 2017;Patel et al, 2017;Hasanuzzaman et al, 2018;Locato et al, 2016;Mostofa et al, 2015;Asgher et al, 2017), multiple abiotic (Fancy et al, 2017;Santisree et al, 2015;Parankusam et al, 2017;Adimulam et al, 2017;Tossi et al, 2012;Sehrawat et al, 2013;Ziogas et al, 2013) and biotic stress responses in plants (Vaishnav et al, 2018). In addition, a number of studies focused on describing the crucial role of NO in moderating various plant hormone-mediated development and stress responses (Asgher et al, 2017).…”

“…While, ABA failed to induce stomatal closure in Atnoa1and nia1nia2 mutants of Arabidopsis thaliana having reduced endogenous NO levels, NO-deficient triple mutant nia1nia2noa1-2 plants were hypersensitive to dehydration and ABA treatment in stomatal closure providing genetic evidence for the involvement of NO in ABA-mediated stomatal closure (Planchet et al, 2014;Lozano-Juste and León, 2011). Furthermore, the overaccumulation of NO in guard cells of Arabidopsis thaliana GSNO reductase mutant (gsnor1-3) has led to the defective ABA-induced stomatal closure due to the constitutive S-nitrosylation of open stomata 1 (OST1) reinforcing NO as a key intermediate in ABA-induced stomatal closure (Adimulam et al, 2017). Moreover, reduced NO accumulation and stomatal closure were observed in respiratory burst oxidase homolog mutant of Arabidopsis thaliana having a mutation in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase suggesting a link between H 2 O 2 and NO accumulation (She et al, 2004).…”