盐藻叶绿素荧光非光化学猝灭产生的条件和主要组分的检测

DETECTING THE FORMATION AND COMPONENTS OF NON- PHOTOCHEMICAL QUENCHING OF CHLOROPHYLL FLUORESCENCE IN DUNALIELLA SALINA 1009

实验用盐藻取自天津溏沽轻工业部制盐研究所 ,应用叶绿素荧光技术检测盐藻悬浮液在暗适应或稳态光合作用下的荧光产量 (光化学荧光猝灭 qP和非光化学荧光猝灭 qN的进程 )和在稳态后黑暗期间荧光产量的恢复 (qN的暗弛豫动力学 )。通过改变诱导光强、脉冲频率和脉冲强度 ,寻找适当的条件以区分光诱导期间的qP、qN和随后黑暗期间qN的快 (qf)、中 ( qm)、慢 ( qs)三个组分。结果表明 ,qN的快相 (qf)仅在相对高的诱导光强 [>1 50 μE/(m2 ·s) ]下出现 ,它被尼日利亚菌素抑制 ,属于高能态猝灭 ( qE)。在大多数情况下 ,qE是 qN的最主要组分 ,它的出现表明了通过增加能量耗散可以避免强光破坏光合器官的保护机制的启动。

By using saturated pulse technology, we examined the effects of light pulse intensities, light pulse frequencies, and inducing light (actinic light) intensities on photochemical (qP) and non-photochemical quenching (qN) of chlorophyll fluorescence during light illumination, and the dark relaxation after reaching photosynthetic steady-state condition in Dunaliella salina 1009. The results show that various components of qN can be resloved by pulse technology in dark relaxation kinetics after the actinic light is turned off. Strdies reveal that three distinct phases of qN relaxation, the ‘fast’ phase (q f),the‘middle’ phase (q m) and the `slow' phase (q s), are presented in Dunaliella salina . The `fast' phase contributed to qE (energy-dependent quenching), a major part of qN under most conditions, which depends on the presence of the thylakoid proton gradient (ΔpH). qE only appears at high light intensities, can be abolished by Nigericin, and recognized to be the principal photoprotective mechanism for energy dissipation in green plants.