细胞外ATP(extracellular ATP, eATP)是目前公认的细胞外信号分子, 参与调控多种环境刺激下植物的生长、发育和防御反应。在植物细胞信号转导过程中, eATP具有双重功能, 其作用主要取决于细胞外基质中eATP的浓度。eATP含量过高或者过低都会导致细胞死亡, 适度水平的eATP则有助于植物的生长和发育。细胞外三磷酸腺苷双磷酸酶(Apyrase)严格控制细胞外基质中eATP的水平, 因此有助于调控植物在逆境条件下的生长和防御反应。该文总结了植物中eATP的发现、产生和清除以及受体和信号转导等研究进展, 重点论述eATP在逆境条件下的生理功能, 并对植物eATP的研究方向作了展望。
Extracellular ATP (eATP) is an important signaling agent in plant growth and the defense response to environmental stimuli. eATP has dual functions in plant cell signaling, which largely depend on its concentration in the extracellular matrix (ECM). A lethal level of eATP (extremely low or high) causes cell death, whereas a moderate level benefits plant growth and development. Ecto-apyrases help controlling eATP content in the ECM and thus contribute to mediating the plant growth and defense response to environmental stress. We summarize the discovery, generation and removal of eATP; the receptors of eATP and eATP signaling in plants; and highlight the physiological function of eATP under stress. We also give a brief outlook of future research of eATP in plants.