《植物生理学报》 2014, 50(11): 1639-1644

细胞外ATP通过刺激NADPH氧化酶缓解水杨酸诱导的细胞死亡

冯汉青*, 白晶月, 管冬冬, 贾凌云, 孙坤

西北师范大学生命科学学院, 兰州730070

通信作者：冯汉青；E-mail: fenghanq@nwnu.edu.cn；Tel: 13008762166

摘　要：

水杨酸(SA)是植物重要的信号分子, 低浓度的SA能够诱导植物的抗病反应, 而高浓度的SA导致植物细胞死亡。本文采用500 μmol•L^-1的SA处理烟草悬浮细胞BY-2, 研究了细胞外ATP在SA诱导的细胞死亡中的作用及可能的机制。结果显示, 外源ATP可缓解SA诱导的细胞死亡水平的上升。另外, SA导致NADPH氧化酶活性下降, 而外源ATP则刺激其活性上升。外源ATP能缓解SA对NADPH氧化酶活性的抑制, 且这种缓解作用可被NADPH氧化酶的抑制剂——二亚苯基碘(DPI)所消除。DPI还可部分消除外源ATP对SA所诱导的细胞死亡的缓解作用。上述结果表明, 胞外ATP通过刺激NADPH氧化酶活性缓解SA诱导的细胞死亡。

关键词：细胞死亡; 胞外ATP; 水杨酸; NADPH氧化酶

收稿：2014-07-03   修定：2014-09-28

资助：国家自然科学基金(31260059和30900105)、教育部科学技术研究重点项目(211190)、甘肃省财政厅高校基本科研业务费项目、西北师范大学基金项目(NWNU-kjcxgc-03-77、NWNU-09-31、NWNU-LKQN-10-32)。

Extracellular ATP Alleviates the Salicylic Acid-Induced Cell Death by Stimulating NADPH Oxidase

FENG Han-Qing*, BAI Jing-Yue, GUAN Dong-Dong, JIA Ling-Yun, SUN Kun

College of Life Sciences, Northwest Normal University, Lanzhou 730070, China

Corresponding author: FENG Han-Qing; E-mail: fenghanq@nwnu.edu.cn; Tel: 13008762166

Abstract:

Salicylic acid (SA) is an important signalling molecule for plant cells. At a lower concentration, SA can induce the resistance responses of plants to bacterial (or viral) pathogens, while at a higher concentration, SA can cause cell death. By using the tobacco (Nicotiana tabacum cv. Bright Yellow-2) cell suspension culture, the role of extracellular ATP in the SA-induced cell death and the possible mechanism were studied in the cell subjected to 500 μmol•L^-1 SA. The results revealed that treatment with exogenous ATP partially alleviated the cell death induced by 500 μmol•L^-1 SA. It was found that treatment with SA decreased the activity of NADPH oxidase, while exogenous ATP increased the activity of NADPH oxidase. Exogenous ATP partially alleviated the inhibition of NADPH oxidase activity by SA. However, the alleviative effect of exogenous ATP on the Sainduced inhibition of NADPH oxidase activity was abolished by diphenylene iodonium (DPI), an inhibitor of NADPH oxidase. And, this inhibitor also partially abolished the alleviative effect of exogenous ATP on the Sainduced cell death. These results indicate that the extracellular ATP can alleviate the SA-induced cell death by stimulating NADPH oxidase activity.

Key words: cell death; extracellular ATP; salicylic acid; NADPH oxidase