Nitric Oxide: The Versatility of an Extensive Signal Molecule

Abstract

Nitric oxide (NO) is a small highly diffusible gas and a ubiquitous bioactive molecule. Its chemical properties make NO a versatile signal molecule that functions through interactions with cellular targets via either redox or additive chemistry. In plants, NO plays a role in a broad spectrum of pathophysiological and developmental processes. Although nitric oxide synthase (NOS)-dependent NO production has been reported in plants, no gene, cDNA, or protein has been isolated to date. In parallel, precise and regulated NO production can be measured from the activity of the ubiquitous enzyme nitrate reductase (NR). In addition to endogenous NO formation, high NO emissions are observed from fertilized soils, but their effects on the physiology of plants are largely unknown. Many environmental and hormonal stimuli are transmitted either directly or indirectly by NO signaling cascades. The ability of NO to act simultaneously on several unrelated biochemical nodes and its redox homeostatic properties suggest that it might be a synchronizing molecule in plants.

An extensive microarray analysis of AAL-toxin-induced cell death in Arabidopsis thaliana brings new insights into the complexity of programmed cell death in plants

“…Despite the progress in revealing the role of NO in PCD, there is still debate about the main source of NO in plants. There are at least two potential sources: nitrate reductase and the pathogen-inducible P protein of the glycine decarboxylase complex [31,33]. In our experiments, we observed induction of one of the genes encoding nitrate reductase, but the significance of this finding remains to be elucidated.…”

“…All these results together suggest that genes regulated by ethylene and ROS are important modulators of plant PCD. In recent years, NO has emerged as a versatile signalling molecule regulating a myriad of biological processes in plants, including cell death responses [31,32]. We showed that generation of NO is important for the enhancement of AAL-toxin-induced cell death as plants unable to synthesize NO were significantly compromised in the PCD response.…”

Roles of ion channels and transporters in guard cell signal transduction

“…Production of ROS such as hydrogen peroxide (H 2 O 2 ) and the reactive nitrogen species nitric oxide (NO) in response to ABA are recently discovered signaling mechanisms in guard cells [73][74][75][76]. Pharmacological manipulations coupled with mutant analysis of both ROS and NO pathways indicate that ABA-induced H 2 O 2 production stimulates NO production and NO is required for H 2 O 2 induced-stomatal closure.…”

Study of interaction effect between triacontanol and nitric oxide on alleviating of oxidative stress arsenic toxicity in coriander seedlings

“…It is reported that TRIA after initial application elicits a metabolite or a secondary messenger, 9-β-L(+) adenosine, which rapidly induces a variety of physiological responses, and influences the activities of enzymes involved in carbohydrate metabolism (dry weight increase) (Khan et al 2007;Naeem et al 2009;Li et al 2016). Nitric oxide (NO) is a free radical involved in numerous and diverse physiological processes in plants (Lamattina et al 2003). Evidence has been obtained for the involvement of NO in plant growth and development, as well as in defense responses (Lamattina et al 2003;Yu et al 2005).…”

“…Nitric oxide (NO) is a free radical involved in numerous and diverse physiological processes in plants (Lamattina et al 2003). Evidence has been obtained for the involvement of NO in plant growth and development, as well as in defense responses (Lamattina et al 2003;Yu et al 2005). Recently, an increasing number of articles have reported the effects of exogenous NO on alleviating HM toxicity in various plants (Jin et al 2010;Xiong et al 2010;Panda et al 2011).…”