一氧化氮在植物响应重金属胁迫中的作用

The Role of Nitric Oxide in Plant Response to Heavy Metal Stress

一氧化氮(Nitric oxide,NO)是一种具有扩散性的气体分子,在哺乳动物中被鉴定为血管内皮细胞舒张因子,是一种有效的内源性血管舒张药。植物也具有合成和释放NO的能力,NO在植物中参与多种生理过程和胁迫响应。因此,NO被认为是植物及动物体内重要的气体信号分子。近年来,由于各种人类活动的影响导致重金属对农业生态环境造成了越来越严重的污染,威胁农作物生产与食品安全。尽管重金属影响植物生长发育的机制并不完全清楚,但越来越多的证据显示NO是植物体内响应重金属胁迫的重要成分之一。就目前重金属胁迫对植物内源NO的代谢以及外源NO对植物重金属毒害的影响的研究进展进行了综述。

Nitric oxide （NO） is a diffusible gaseous molecule fist identifid in mammalian systems as the endothelium-derived relaxing factor, a potent endogenous vasodilatator. NO is also synthesized and released by plants, where it is involved in several physiological processes and in adaptative response against different stresses. Hence, NO is considered to be a general signal molecule in plant and animal cells. In recent years, heavy metals （HMs）, naturally present or added to soil through diverse anthropogenic activities, have become a problem of agricultural and environmental significance. Although the mechanism by which HMs affect plants integrity is not fully understood, there is increasing evidence suggesting that an important component of the responses against HM stress is NO. This paper presents an overview on the effects of HMs on endogenous NO content. In addition, the role of exogenous-applied NO in alleviating HM toxicity is summarized and discussed.