Roles of hydrogen sulfide and nitric oxide in the alleviation of cadmium-induced oxidative damage in alfalfa seedling roots
Roles of hydrogen sulfide and nitric oxide in the alleviation of cadmium-induced oxidative damage in alfalfa seedling roots
复制标题
硫化氢和一氧化氮在减轻镉诱导的苜蓿幼苗根部氧化损伤中的作用
DOI：
10.1007/s10534-012-9551-9
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发表时间：
2012-06-01
期刊：
影响因子：
3.5
通讯作者：
Shen, Wenbiao
中科院分区：
文献类型：
--
作者：
Li, Le;Wang, Yanqin;Shen, Wenbiao
尽管硫化氢 (H2S) 和一氧化氮 (NO) 是重要的内源信号或生物调节剂，参与植物生长和对抗非生物胁迫反应的许多重要方面，但有关它们相互作用的信息却很少。在本研究中，我们评估了 H2S 和 NO 对暴露于镉 (Cd) 胁迫的苜蓿 (Medicago sativaL.) 植物的影响。用 H2S 供体硫氢化钠 (NaHS) 和众所周知的 NO 供体硝普钠 (SNP) 进行预处理可降低 Cd 毒性。与单独受镉胁迫的植物相比，脂质过氧化的减少以及幼苗生长抑制和镉积累的改善支持了这一结论。抗氧化酶（包括超氧化物歧化酶、过氧化物酶和抗坏血酸过氧化物酶）的总活性和相应转录物受到差异调节，从而减轻氧化损伤。上述 H2S 的影响可被 NO 特异性清除剂 2-(4-羧基苯基)-4,4,5,5-四甲基咪唑啉-1-氧基-3-氧化钾盐 (cPTIO) 逆转。采用激光共聚焦扫描显微镜结合Greiss试剂法进一步研究结果表明，无论是否施加Cd，NaHS预处理后NO产生均显着增加，而cPTIO均明显抑制NO产生。 NO 产生的这些减少与与镉毒性相关的夸大症状是一致的。总之，上述结果表明，NO 参与了 NaHS 诱导的苜蓿幼苗 Cd 毒性的减轻，并且还表明 H2S 和 NO 之间存在交互作用，导致非生物胁迫耐受性增加。
Despite hydrogen sulfide (H2S) 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 H2S and NO on alfalfa (Medicago sativaL.) plants exposed to cadmium (Cd) stress. Pretreatment with an H2S 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 H2S 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 H2S and NO responsible for the increased abiotic stress tolerance.