Overexpression of Rat Neurons Nitric Oxide Synthase in Rice Enhances Drought and Salt Tolerance

Abstract

Nitric oxide (NO) has been shown to play an important role in the plant response to biotic and abiotic stresses in Arabidopsis mutants with lower or higher levels of endogenous NO. The exogenous application of NO donors or scavengers has also suggested an important role for NO in plant defense against environmental stress. In this study, rice plants under drought and high salinity conditions showed increased nitric oxide synthase (NOS) activity and NO levels. Overexpression of rat neuronal NO synthase (nNOS) in rice increased both NOS activity and NO accumulation, resulting in improved tolerance of the transgenic plants to both drought and salt stresses. nNOS-overexpressing plants exhibited stronger water-holding capability, higher proline accumulation, less lipid peroxidation and reduced electrolyte leakage under drought and salt conditions than wild rice. Moreover, nNOS-overexpressing plants accumulated less H2O2, due to the observed up-regulation of OsCATA, OsCATB and OsPOX1. In agreement, the activities of CAT and POX were higher in transgenic rice than wild type. Additionally, the expression of six tested stress-responsive genes including OsDREB2A, OsDREB2B, OsSNAC1, OsSNAC2, OsLEA3 and OsRD29A, in nNOS-overexpressing plants was higher than that in the wild type under drought and high salinity conditions. Taken together, our results suggest that nNOS overexpression suppresses the stress-enhanced electrolyte leakage, lipid peroxidation and H2O2 accumulation, and promotes proline accumulation and the expression of stress-responsive genes under stress conditions, thereby promoting increased tolerance to drought and salt stresses.

S‐nitrosoglutathione spraying improves stomatal conductance, Rubisco activity and antioxidant defense in both leaves and roots of sugarcane plants under water deficit

“…Some studies have reported nitric oxide (NO) action in plants under drought (Santisree et al , Farnese et al ), with this molecule cooperating in abscisic acid (ABA)‐induced stomatal closure (Neill et al ) and also increasing drought tolerance in Vicia faba (Garcia‐Mata and Lamattina ). In fact, NO is an important plant messenger mediating various physiological and biochemical processes, which can directly alter protein structure and activity (Cai et al ). NO has a multifunctional role and its effects on plants can be beneficial or not, depending on its concentration and type of donor when supplied.…”

Evidence towards the involvement of nitric oxide in drought tolerance of sugarcane

“…For instance, Arasimowicz-Jeloneka et al (2009) found that Cucumis sativus subjected to mild water deficit enhanced NO synthesis in root cells, with an intense NO production in root elongation zone. Although several reports have shown increased NO production under drought (Filippou et al, 2011;Fan and Liu, 2012;Xiong et al, 2012;Cai et al, 2015), there is no information about how plant species/varieties differ in NO production and how this differential NO production is related to drought tolerance. The aim of this work was to test the hypothesis that drought-tolerance in sugarcane is associated with NO production and metabolism, with the more drought tolerant genotype presenting higher NO accumulation in plant tissues.…”

Fine Mapping of a New Lesion Mimic and Early Senescence 2 (lmes2) Mutant in Rice

“…Hydrogen Peroxide and Superoxide Content, Proline Content, and Activity of Catalase, Superoxide Dismutase, and Peroxidase At the tillering stage, the first, second, and third fully opened leaves from topmost leaf of the wild-type and lmes2 mutant were collected and used to measure the ROS and proline contents as well as CAT, SOD, and POD activity as described previously (Qiu et al, 2008;Cai et al, 2015;Kar and Mishra, 1976). The H 2 O 2 assay kit (A064), antisuperoxide anion and production of superoxide anion radical assay kit (A052), proline content assay kit (A107), CAT assay kit (A007-1), SOD activity assay kit (A001-1), and POD activity assay kit (A084-3) were provided by the Nanjing Jiancheng Technology Company (China).…”