非生物胁迫对烟草悬浮细胞胞内和胞外ATP水平的影响

以烟草悬浮细胞BY-2（Nicotiana tabacum ‘Bright Yellow-2’）为材料，研究了NaCl、PEG（6000）、低温3种非生物胁迫对细胞内ATP（intracellular ATP，iATP）和细胞外ATP（extracellular ATP，eATP）水平的影响。结果显示：50~200 mmol·L^-1 NaCl处理导致烟草悬浮细胞膜通透性显著增加（P<0.05），100和200 mmol·L^-1 NaCl处理时iATP和eATP水平显著降低（P<0.05）。随着PEG质量浓度的增加（50、100、200 g·L^-1），烟草悬浮细胞膜通透性和eATP水平逐渐增加，其中在200 g·L^-1 PEG处理时eATP水平显著增加至对照的3.4倍（P<0.05），而iATP水平则在200 g·L^-1 PEG处理时显著降低至对照的0.5倍（P<0.05）。0~10 ℃低温处理后，烟草悬浮细胞膜通透性和iATP水平呈不同程度增加，其中0 ℃处理时iATP水平增加至对照的1.9倍，而eATP水平在10 ℃时显著下降至对照的0.8倍（P<0.05）。上述结果表明，虽然植物的iATP是eATP的来源，但在非生物胁迫下iATP不是影响eATP水平变化的唯一因素，细胞运输ATP等因素可能也影响着eATP的水平。

Effects of Abiotic Stresses on the Intracellular and Extracellular ATP Levels of Tobacco Suspension Cells

In this study， the effects of NaCl， PEG（6000） and low temperature stresses on the levels of iATP （intracellular ATP） and eATP（extracellular ATP） of tobacco suspension cells BY-2（Nicotiana tabacum ‘Bright Yellow-2’） were studied respectively. The results showed that the tobacco suspension cells treated with 50-200 mmol·L^-1 NaCl significantly increased membrane permeability（P<0.05）， the levels of iATP and eATP decreased significantly at 100 and 200 mmol·L^-1 NaCl stresses（P<0.05）. With the increase of PEG mass concentration（50， 100 and 200 g·L^-1）， the membrane permeability and eATP level increased. Under 200 g·L^-1 PEG stress， eATP level increased significantly to 3.4-fold of the control（P<0.05）， iATP level decreased significantly to 0.5-fold of the control（P<0.05）. After the treatment with low temperature at 0-10 ℃， the membrane permeability and iATP level increased to different extents. iATP level increased to 1.9-fold of the control at 0 ℃， while eATP level decreased significantly to 0.8-fold the control at 10 ℃（P<0.05）. The above results indicate that iATP is the source of eATP in plant cells， iATP level is not the only factor that affects eATP level under abiotic stresses. The way in which plant cells transport ATP and other factors may affect eATP level under abiotic stresses.