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作 者 ：冯汉青；白晶月；管冬冬；贾凌云；孙坤

期 刊 ：植物研究 2015年 35卷 5期 页码：710-715

关键词：细胞死亡；铜离子；胞外H2O2；NADPH氧化酶；

Keywords:celldeath, copper, extracellularH2O2, NADPHoxidase,

摘 要 ：以烟草悬浮细胞BY-2(Nicotiana tabacum L.cv.Bright Yellow-2)为材料,探讨了在铜离子胁迫下植物细胞死亡发生过程中胞外H₂O₂及NADPH氧化酶所扮演的角色。实验结果表明,随着外源CuCl₂浓度的上升(从0~700 μmol·L^-1)，细胞死亡水平不断上升，且胞外H₂O₂的水平也不断增加。在300 μmol·L^-1的CuCl₂诱导细胞死亡的过程中,加入H₂O₂清除剂N-N-二甲基硫脲(DMTU)降低了胞外CuCl₂胁迫下H₂O₂含量增加的同时也降低了细胞死亡水平的上升,这一观察表明了铜离子胁迫所导致的细胞死亡的发生和胞外H₂O₂的增加有关。进一步的研究表明,300 μmol·L^-1 CuCl₂的胁迫导致了NADPH氧化酶活性的显著性上升,而加入NADPH氧化酶的抑制剂（二亚苯基碘，DPI,)则降低了CuCl₂胁迫所导致的细胞死亡和胞外H₂O₂含量的上升。上述结果表明，胞外H₂O₂和NADPH氧化酶参与了CuCl₂对植物细胞死亡的诱导作用。

Abstract:By using the tobacco (Nicotiana tabacum cv. Bright Yellow-2) cell suspension culture, we studied the roles of extracellular H₂O₂ and NADPH oxidase in the copper-induced cell death. With the increase of exogenous CuCl₂ from 0 to 700 μmol·L^-1, the level of cell death were increased followed by the increase of extracellular H₂O₂. In the cell subjected to 300 μmol·L^-1 CuCl₂, the addition of exogenous dimethyl thiourea (DMTU, a scavenger of H₂O₂) alleviated the increases of both the cell death level and the production of extracellular H₂O₂, which were induced by CuCl₂(300 μmol·L^-1). The copperinduced increase in the cell death was associated with the increase of extracellular H₂O₂. The CuCl₂(300 μmol·L^-1) stress induced an increase of the activity of NADPH oxidase. The addition of diphenylene iodonium (DPI, an inhibitor of NADPH oxidase) alleviated the increases of both the cell death level and the production of extracellular H₂O₂, which were induced by CuCl₂ (300 μmol·L^-1). Our results indicate that extracellular H₂O₂ and NADPH oxidase are involved in the copper-induced cell death.

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