Influence of nitric oxide in protection of tomato seedling against oxidative stress induced by osmotic stress

Abstract

Osmotic stress associated with drought and salinity is a serious problem that inhibits the growth of plants mainly due to disturbance of the balance between production of ROS and antioxidant defense and causes oxidative stress. In this research, sodium nitroprusside (SNP) was used as NO donor in control and droughtstressed plants, and the role of NO in reduction of oxidative damages were investigated. In this study, we observed that SNP pretreatment prevented drought-induced decrease in RWC and membrane stability index, increase in lipid peroxidation and lipoxygenase activity and increase in hydrogen peroxide content. However, pretreatment of plants with SNP and phenyl 4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (a NO scavenger) reversed the protective effects of SNP suggesting that protective effect by SNP is attributable to NO release. In addition, the relationship between these defense mechanisms and activity of antioxidant enzymes were checked. Results showed that in drought-stressed plants ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and catalase activities were elevated over the controls, while GR decreased under drought condition. Activity of GPX was inhibited under SNP pretreatment in drought-stressed plants specially, while the activity of APX and GR increased under SNP pretreatment and it seems that under this condition APX had a key role of detoxification of ROS in tomato plants. This result corresponded well with ASA and total acidsoluble thiols content. Therefore, reduction of droughtinduced oxidative damages by NO in tomato leaves is most likely mediated through either NO ability to scavenge active oxygen species or stimulation of antioxidant enzyme such as APX.

Effect of exogenous arginine on alleviation of oxidative damage in tomato plant underwater stress

“…In the present study, application of arginine, significantly increased the SOD activity, and suggested that application of this compound could promote the conversion of O × 2 into H 2 O 2 and O 2 , which is an important step in protecting the cell. The same result observed in SNP treated plants under drought stress (Nasibi and Kalantari 2009). If the produced H 2 O 2 cannot be scavenged efficiently, it can interact with O × 2 to form highly reactive hydroxyl radicals that are thought to be primarily responsible for oxygen toxicity in the cell.…”

“…In previous research, we applied Sodium nitroprosside (SNP), an NO donor to counteract the effect of drought stresses on tomato plants (Nasibi and Kalantari 2009). However not any data are available on the effect of exogenous arginine as a precursor of NO in the possible antioxidative responses of plants against water stress.…”

Effect of arginine pre-treatment on nickel accumulation and alleviation of the oxidative stress in Hyoscyamus niger

“…Ni excess in the environment also decreases chlorophyll content and growth in metal sensitive plants (Boominathan and Doran, 2002). Many abiotic environmental stresses including salinity, drought stress, temperature extremes, and metal toxicity disrupt the redox homeostasis of cells and exert a wide range of adverse effects on plant growth and metabolism (Sharma and Dubey, 2007;Nasibi and Kalantari, 2009). These stressful conditions induce overproduction of reactive oxygen species (ROS).…”

Exogenous nitric oxide protects against salt-induced oxidative stress in the leaves from two genotypes of tomato (Lycopersicom esculentum Mill.)

“…NO has also been involved in responses to abiotic and biotic stresses. It has been reported to exert a protective effect in response to drought stress (Lei et al 2007;Zhao et al 2008;Nasibi and Kalantari 2009), heat stress (Song et al 2006), heavy metal stress (Kopyra et al 2006;Singh et al 2008) and UV radiation stress (Shi et al 2005). The involvement of NO in salinity tolerance has drawn much attention in the past few years (Molassiotis et al 2010).…”