Laboratoire de Biologie végétale, Université de Perpignan, Avenue de Villeneuve, F-66025, Perpignan Cedex, France.
Photosynth Res. 1987 Jan;11(2):131-9. doi: 10.1007/BF00018271.
In Phaeodactylum tricornutum cells kept 30 min in the dark, induction of fluorescence showed the well-known levels OIDPSMT. The decrease of MT was the most important when the intensity of excitation light was high. It was mainly due to the photochemical quenching. After addition of DCMU (2 to 20 μM), a quenching qE was still observed: this quenching, cancelled by NH4Cl (2 to 20 mM) is attributed to ΔpH. This qE was also inhibited by antimycin, an inhibitor of cyclic phosphorylation and may be of chlororespiration above plastoquinones. Anaerobiosis also decreased it. We can infer that chlororespiration also plays a part in the formation of the ΔpH in the presence of DCMU. After 30 mn of preillumination in red light, the levels P and M were lower and the quenching in presence of DCMU was no more observed: thus, neither the chlororespiration nor the cyclic phosphorylation were active, unless the activity of ATPase was much more important. So, in diatoms, one at least of the above cited phenomena can be modulated by light.
在黑暗中培养 30 分钟的菱形藻细胞，诱导荧光显示出众所周知的 OIDPSMT 水平。当激发光强度较高时，MT 的减少最为明显。这主要是由于光化学猝灭。加入 DCMU（2 到 20 μM）后，仍然观察到 qE 猝灭：这种猝灭被 NH4Cl（2 到 20 mM）取消，归因于 ΔpH。这种 qE 也被抗霉素抑制，抗霉素是环状磷酸化的抑制剂，可能与质体醌上方的氯呼吸有关。厌氧条件也会降低它。我们可以推断，在 DCMU 存在下，氯呼吸也参与了 ΔpH 的形成。在红光预照 30 分钟后，P 和 M 的水平较低，并且在 DCMU 存在下观察不到猝灭：因此，除非 ATP 酶的活性更为重要，否则氯呼吸或环状磷酸化都不活跃。因此，在硅藻中，至少有一种上述现象可以被光调节。
