Roles of hydrogen sulfide and nitric oxide in the alleviation of cadmium-induced oxidative damage in alfalfa seedling roots

Abstract

Despite hydrogen sulfide (H(2)S) and nitric oxide (NO) are important endogenous signals or bioregulators involved in many vital aspects of plant growth and responses against abiotic stresses, little information was known about their interaction. In the present study, we evaluated the effects of H(2)S and NO on alfalfa (Medicago sativa L.) plants exposed to cadmium (Cd) stress. Pretreatment with an H(2)S donor sodium hydrosulfide (NaHS) and well-known NO donor sodium nitroprusside (SNP) decreased the Cd toxicity. This conclusion was supported by the decreases of lipid peroxidation as well as the amelioration of seedling growth inhibition and Cd accumulation, in comparison with the Cd-stressed alone plants. Total activities and corresponding transcripts of antioxidant enzymes, including superoxide dismutase, peroxidase and ascorbate peroxidase were modulated differentially, thus leading to the alleviation of oxidative damage. Effects of H(2)S above were reversed by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), the specific scavenger of NO. By using laser confocal scanning microscope combined with Greiss reagent method, further results showed that NO production increased significantly after the NaHS pretreatment regardless of whether Cd was applied or not, all of which were obviously inhibited by cPTIO. These decreases of NO production were consistent with the exaggerated syndromes associated with Cd toxicity. Together, above results suggested that NO was involved in the NaHS-induced alleviation of Cd toxicity in alfalfa seedlings, and also indicated that there exists a cross-talk between H(2)S and NO responsible for the increased abiotic stress tolerance.

Hydrogen sulfide is involved in the chilling stress response in Vitis vinifera L.

“…Recent studies in plants revealed that H 2 S plays multiple roles in the modulation of various physiological processes [3], such as copper, cadmium, drought, salinity and heat et al [6][7][8][9][10]. In addition, our results indicate that the content of H 2 S was rapidly increased by low temperature.…”

“…Many data indicate that most of the endogenously synthesized H 2 S occurred via L-cysteine desulfhydrase (LCD, EC4.4.1.1) and D-cysteine desulfhydrase (DCD, EC4.4.1.15) in high plants [2][3][4][5]. Recent studies show that H 2 S is involved not only in plant responses to drought and copper stresses but also in tolerance to salinity, heat, cadmium, boron and chromium stresses [6][7][8][9][10]. It is reported that exogenous H 2 S can enhance the resistance of plants to drought stress [11][12][13][14] and copper stress [15,16] by improving the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD).…”

Hydrogen Sulfide Generated byl-Cysteine Desulfhydrase Acts Upstream of Nitric Oxide to Modulate Abscisic Acid-Dependent Stomatal Closure

“…As for animal systems, in plants, there is controversial evidence about H 2 S-NO interaction. On one hand, it was shown that H 2 S acts upstream of NO in root organogenesis and heavy metal toxicity (Zhang et al, 2009a;Li et al, 2012). On the other hand, H 2 S was reported to act downstream of NO in the ethylene-induced stomatal closure and in the resistance to heat stress (Liu et al, 2012;Li et al, 2013b).…”

Negative regulation of autophagy by sulfide in Arabidopsis thaliana is independent of reactive oxygen species

“…Alterations of hydrogen sulfide metabolism have important pathological consequences, establishing the clinical relevance of this molecule (Łowicka and Bełtowski, 2007;Szabó, 2007;Wang, 2012). In addition to the protective effects of hydrogen sulfide against a wide array of different stresses that have been demonstrated in plants (Zhang et al, 2008Wang et al, 2010;Jin et al, 2011;Dawood et al, 2012;Li et al, 2012aLi et al, , 2012bCheng et al, 2013;Christou et al, 2013;Sun et al, 2013), this molecule has also been shown to regulate plant processes that are critical for plant performance, such as photosynthesis (Chen et al, 2011), stomatal movement (García-Mata and Lamattina, 2010;Lisjak et al, 2010;Scuffi et al, 2014), and autophagy (Álvarez et al, 2012b; Gotor et al, 2013). In this study, we provide new experimental evidence that, together with our previous findings, demonstrates the role of hydrogen sulfide in regulating the progression of autophagy independently of the condition in which the autophagy originates.…”