图5. 同步测量莱茵衣藻P515信号和叶绿素荧光
将莱茵衣藻野生型(浓度约30 μg·mL^-1)暗适应20分钟, 放入荧光仪的测量室, 分别打开P515/535模块和叶绿素荧光模块的测量光, 测定初始荧光产量(F_o)。打开饱和闪光(635 nm, 6000 μmol·m^-2·s^-1, 持续时间250 ms), 测定黑暗状态下的最大荧光产量(F_m)。之后打开活化光(635 nm, 1500 μmol·m^-2·s^-1), 持续照光140秒, 期间每隔60秒施加1次饱和闪光, 测定光下最大荧光产量(F_m′)。活化光关闭后测定质子动力势(pmf)及其组分(ΔΨ和ΔpH), 与此同时每隔60秒施加1次饱和闪光, 检测黑暗状态下的荧光产量是否恢复到最大荧光产量(F_m)。F_o: 初始荧光产量; F_m: 最大荧光产量; F_m′: 光下最大荧光产量; F_s: 稳态荧光产量; Actinic light: 活化光; Saturating pulse: 饱和闪光; pmf: 质子动力势; ΔΨ: 跨膜电势; ΔpH: 跨膜质子梯度

Figure 5. Simultaneous measurement of the P515 signal and fluorescence in Chlamydomonas reinhardtii
The C. reinhardtii cells (WT, about 30 μg·mL^-1) were placed in the chamber of the chlorophyll fluorometer after dark adaptation for 20 minutes. The measuring lights of the P515/535 module and the chlorophyll fluorescence module were turned on respectively to determine the original fluorescence yield (F_o). Then a saturating pulse (635 nm, 6000 μmol·m^-2·s^-1, duration 250 ms) was turned on to detect the maximal fluorescence yield (F_m) in darkness. Then an actinic light (635 nm, 1500 μmol·m^-2·s^-1) was turned on for 140 seconds, during which a saturating flash was applied every 60 seconds to detect the maximum fluorescence yield (F_m') under light. The proton motive force (pmf) and its components (ΔΨ and ΔpH) were measured after the actinic light was turned off, meanwhile a saturating pulse was applied every 60 seconds to check whether the fluorescence yield was restored to the maximum fluorescence yield (F_m) in darkness. F_o: Original fluorescence yield; F_m: Maximal fluorescence yield; F_m′: Maximal fluorescence yield under light; F_s: Steady state fluorescence yield; pmf: Proton motive force; ΔΨ: Transmembrane potential; ΔpH: Transmembrane proton gradient