中文摘要：

细胞外ATP是植物体中许多生理过程的调节信号.胞外ATP可以影响铜离子诱导的细胞死亡和H2O2的产生.100~700/μmol/L CuCl2导致烟草悬浮细胞的死亡量显著上升,而且胞内H2O2和胞外H2O2的含量也随之上升.选择了300/μmol/L CuCl2研究铜离子导致的细胞死亡量上升和H2O2产生的过程.结果表明,此浓度的CuCl2提升了NADPH氧化酶的活性,而加入DPI（NADPH氧化酶抑制剂）缓解了CuCl2引起的细胞死亡和H2O2的产生,这说明CuCl2引起细胞死亡和H2O2产生与NADPH氧化酶活性的增加相关.加入50μmol/L ATP进一步增加了CuCl2引起的细胞死亡、H2O2的产生、NADPH氧化酶.而DPI预处理后,外源ATP并未引起变化.这一实验表明,胞外ATP可以通过刺激NADPH氧化酶影响铜离子引起的细胞活性和H2O2产生的变化.

英文摘要：

Extracellular ATP（eATP） has been considered as a mediating signal in several physiological processes of plants.In this article we showed that eATP can affect the copperinduced cell death and hydrogen peroxide（H2O2） production.CuCl2 at concentrations from100 to 700 μmol/L caused a significant increase of cell death in tobacco（Nicotiana tabacum L） suspension cultures,and this increase of cell death level was followed with increases of both intracellular and extracellular H2O2 production.The cells exposed to 300μmol/L CuCl2 were chosen to investigate the mechanisms for the copper-induced increases of cell death and H2O2 production and the effect on this process.The results showed that the treatmentwith CuCl2 at this concentration increased the activity of NADPH oxidase,and addition of DPI（diphenylene iodonium,an inhibitor of NADPH oxidase） alleviated the CuCl2-induced increases of cell death and H2O2 production,indicating that the CuCl2-induced increases of cell death and H2O2 production were related to an increase of the activity of NADPH oxidase.Addition of exogenous ATP at 50 μmol/L into the CuCl2-stressed cells further enhanced the levels of cell death,H2O2 production,and NADPH oxidase activity.However,in the presence of DPI,exogenous ATP failed to do so.These observations indicated that eATP can affect the copper-induced changes of cell viability and H2O2 production by stimulating NADPH oxidase.