Effect of exogenous nitric oxide on antioxidative system and S-nitrosylation in leaves of Boehmeria nivea (L.) Gaud under cadmium stress

Abstract

Cadmium (Cd)-induced growth inhibition is one of the primary factors limiting phytoremediation effect of Boehmeria nivea (L.) Gaud in contaminated soil. Sodium nitroprusside (SNP), a donor of nitric oxide (NO), has been evidenced to alleviate Cd toxicity in many plants. However, as an important mechanism of NO in orchestrating cellular functions, S-nitrosylation is still poorly understood in its relation with Cd tolerance of plants. In this study, higher exogenous NO levels were found to coincide with higher S-nitrosylation level expressed as content of S-nitrosothiols (SNO). The addition of low concentration (100 μM) SNP increased the SNO content, and it simultaneously induced an alleviating effect against Cd toxicity by enhancing the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) and reduced the accumulation of H2O2 as compared with Cd alone. Application of S-nitrosoglutathione reductase (GSNOR) inhibitors dodecanoic acid (DA) in 100 μM SNP group brought in an extra elevation in S-nitrosylation level and further reinforced the effect of SNP. While the additions of 400 μM SNP and 400 μM SNP + 50 μM DA further elevated the S-nitrosylation level, it markedly weakened the alleviating effect against Cd toxicity as compared with the addition of 100 μM SNP. This phenomenon could be owing to excess consumption of glutathione (GSH) to form SNO under high S-nitrosylation level. Therefore, the present study indicates that S-nitrosylation is involved in the ameliorating effect of SNP against Cd toxicity. This involvement exhibited a concentration-dependent property.

Cross Talk between Nitric Oxide and Phytohormones Regulate Plant Development during Abiotic Stresses

“…Hence, it may be speculated that NO and S interact to modulate ABA and ET levels in guard cells that may inluence the stomatal and photosynthetic response under salt stress conditions. NO combines with GSH to generate S-nitrosoglutathione (GSNO), leading to enhanced S requirement of plants for improved tolerance under environmental stress conditions [99,100]. Coordinated efect of NO and S regulated the utilization of S and GSH resulting in improved growth and photosynthetic activity in salt-stressed mustard plants [86].…”

Alternative Pathway is Involved in Nitric Oxide-Enhanced Tolerance to Cadmium Stress in Barley Roots

“…Nitric oxide (NO), known as a multifunctional signaling molecule, has been widely reported upon in recent years. It not only functions in plant physiological processes, but also defends against various environmental stresses [11][12][13], even mitigating heavy metal toxicity [14,15]. There are enzymatic and non-enzymatic systems that produce NO [16,17].…”

Enhancement of tolerance of Ganoderma lucidum to cadmium by nitric oxide

“…The mycelia (0.3 g) were ground in liquid nitrogen and 2.7 ml of phosphate buffer (pH 7.4) was added. After centrifuged at 10,000 rpm for 10 min, the supernatant was used for measuring H 2…”

“…Nitric oxide (NO), a multifunctional bioactive molecule, has been reported as a signal molecule participating in regulating many aspects of physiological processes and responses to abiotic stresses in plants . NO is a dual functional molecule.…”

“…Nitric oxide (NO), a multifunctional bioactive molecule, has been reported as a signal molecule participating in regulating many aspects of physiological processes and responses to abiotic stresses in plants [2,10] through enhancing the activities of antioxidant enzymes, such as SOD, POD, and CAT [11,12] or reacting with different ROS [13,14], while high levels of NO enhance ROS production [12]. Recently, studies have reported that NO is involved in the regulation of fungal defensive responses.…”