Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361005, China; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Key Laboratory for Subtropical Wetland Ecosystem Research of MOE, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361005, China.
J Hazard Mater. 2015 Oct 30;297:173-82. doi: 10.1016/j.jhazmat.2015.04.077. Epub 2015 Apr 29.
Nitric oxide (NO) has been found to function in enhancing plant tolerance to various environmental stresses. However, role of NO in relieving zinc oxide nanoparticles (ZnO NPs)-induced phytotoxicity remains unknown. Here, sodium nitroprusside (SNP, a NO donor) was used to investigate the possible roles and the regulatory mechanisms of NO in counteracting ZnO NPs toxicity in rice seedlings. Our results showed that 10 μM SNP significantly inhibited the appearance of ZnO NP toxicity symptoms. SNP addition significantly reduced Zn accumulation, reactive oxygen species production and lipid peroxidation caused by ZnO NPs. The protective role of SNP in reducing ZnO NPs-induced oxidative damage is closely related to NO-mediated antioxidant system. A decrease in superoxide dismutase activity, as well as an increase in reduced glutathione content and peroxidase, catalase and ascorbate peroxidase activity was observed under SNP and ZnO NPs combined treatments, compared to ZnO NPs treatment alone. The relative transcript abundance of corresponding antioxidant genes exhibited a similar change. The role of NO in enhancing ZnO NPs tolerance was further confirmed by genetic analysis using a NO excess mutant (noe1) and an OsNOA1-silenced plant (noa1) of rice. Together, this study provides the first evidence indicating that NO functions in ameliorating ZnO NPs-induced phytotoxicity.
一氧化氮 (NO) 被发现具有增强植物耐受各种环境胁迫的功能。然而，NO 在缓解氧化锌纳米粒子 (ZnO NPs) 诱导的植物毒性方面的作用尚不清楚。本研究中，使用硝普酸钠 (SNP，NO 供体) 来研究 NO 在拮抗水稻幼苗中 ZnO NPs 毒性中的可能作用和调控机制。结果表明，10 μM SNP 显著抑制了 ZnO NPs 毒性症状的出现。SNP 的添加显著降低了 ZnO NPs 引起的 Zn 积累、活性氧产生和脂质过氧化。SNP 在减少 ZnO NPs 诱导的氧化损伤中的保护作用与 NO 介导的抗氧化系统密切相关。与单独用 ZnO NPs 处理相比，在 SNP 和 ZnO NPs 联合处理下，超氧化物歧化酶活性降低，还原型谷胱甘肽含量增加，过氧化物酶、过氧化氢酶和抗坏血酸过氧化物酶活性增加。相应抗氧化基因的相对转录丰度也发生了相似的变化。利用过量的一氧化氮突变体 (noe1) 和 OsNOA1 沉默植物 (noa1) 进行遗传分析进一步证实了 NO 增强 ZnO NPs 耐受性的作用。综上所述，本研究首次表明 NO 可缓解 ZnO NPs 诱导的植物毒性。
