Zhang Liping, Pei Yanxi, Wang Hongjiao, Jin Zhuping, Liu Zhiqiang, Qiao Zengjie, Fang Huihui, Zhang Yanjie
School of Life Science, Shanxi University, Taiyuan 030006, China.
Oxid Med Cell Longev. 2015;2015:804603. doi: 10.1155/2015/804603. Epub 2015 May 11.
Hydrogen sulfide (H2S) is a cell signal molecule produced endogenously and involved in regulation of tolerance to biotic and abiotic stress in plants. In this work, we used molecular biology, physiology, and histochemical methods to investigate the effects of H2S on cadmium- (Cd-) induced cell death in Chinese cabbage roots. Cd stress stimulated a rapid increase of endogenous H2S in roots. Additionally, root length was closely related to the cell death rate. Pretreatment with sodium hydrosulfide (NaHS), a H2S donor, alleviated the growth inhibition caused by Cd in roots-this effect was more pronounced at 5 μM NaHS. Cd-induced cell death in roots was significantly reduced by 5 μM NaHS treatment. Under Cd stress, activities of the antioxidant enzymes were significantly enhanced in roots. NaHS + Cd treatment made their activities increase further compared with Cd exposure alone. Enhanced antioxidant enzyme activity led to a decline in reactive oxygen species accumulation and lipid peroxidation. In contrast, these effects were reversed by hydroxylamine, a H2S inhibitor. These results suggested that H2S alleviated the cell death caused by Cd via upregulation of antioxidant enzyme activities to remove excessive reactive oxygen species and reduce cell oxidative damage.
硫化氢(H₂S)是一种内源性产生的细胞信号分子,参与植物对生物和非生物胁迫耐受性的调控。在本研究中,我们运用分子生物学、生理学和组织化学方法,研究了H₂S对大白菜根中镉(Cd)诱导的细胞死亡的影响。镉胁迫促使根中内源性H₂S迅速增加。此外,根长与细胞死亡率密切相关。用硫化氢供体硫氢化钠(NaHS)预处理可缓解镉对根生长的抑制作用——在5 μM NaHS时这种作用更为明显。5 μM NaHS处理显著降低了镉诱导的根细胞死亡。在镉胁迫下,根中抗氧化酶的活性显著增强。与单独镉处理相比,NaHS + Cd处理使这些酶的活性进一步增加。抗氧化酶活性增强导致活性氧积累和脂质过氧化作用下降。相反,硫化氢抑制剂羟胺可逆转这些效应。这些结果表明,H₂S通过上调抗氧化酶活性来清除过量的活性氧并减少细胞氧化损伤,从而减轻镉诱导的细胞死亡。