Delphin E, Duval JC, Etienne AL, Kirilovsky D
Photoregulation et Dynamique des Membranes Vegetales, Unite de Recherche Associee 1810, Centre National de la Recherche Scientifique, Ecole Normale Superieure, 46 rue d'Ulm, 75230 Paris cedex 05, France.
Plant Physiol. 1998 Sep;118(1):103-13. doi: 10.1104/pp.118.1.103.
We have previously shown that in the red alga Rhodella violacea, exposure to continuous low intensities of light 2 (green light) or near-saturating intensities of white light induces a DeltapH-dependent PSII fluorescence quenching. In this article we further characterize this fluorescence quenching by using white, saturating, multiturnover pulses. Even though the pulses are necessary to induce the DeltapH and the quenching, the development of the latter occurred in darkness and required several tens of seconds. In darkness or in the light in the presence of 2, 5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, the dissipation of the quenching was very slow (more than 15 min) due to a low consumption of the DeltapH, which corresponds to an inactive ATP synthase. In contrast, under far-red illumination or in the presence of 3-(3,4-dichlorophenyl)-1,1'-dimethylurea (only in light), the fluorescence quenching relaxed in a few seconds. The presence of N, N'-dicyclohexyl carbodiimide hindered this relaxation. We propose that the quenching relaxation is related to the consumption of DeltapH by ATP synthase, which remains active under conditions favoring pseudolinear and cyclic electron transfer.
我们之前已经表明，在红藻紫球藻中，暴露于持续低强度的光2（绿光）或近饱和强度的白光下会诱导一种依赖于ΔpH的PSII荧光猝灭。在本文中，我们通过使用白色、饱和、多周转脉冲进一步表征这种荧光猝灭。尽管脉冲对于诱导ΔpH和猝灭是必要的，但后者的发展发生在黑暗中，并且需要几十秒。在黑暗中或在存在2,5-二溴-3-甲基-6-异丙基对苯醌的光照下，由于ΔpH的低消耗，猝灭的消散非常缓慢（超过15分钟），这对应于无活性的ATP合酶。相比之下，在远红光照射下或在存在3-(3,4-二氯苯基)-1,1'-二甲基脲（仅在光照下）的情况下，荧光猝灭在几秒钟内就会松弛。N,N'-二环己基碳二亚胺的存在阻碍了这种松弛。我们提出，猝灭的松弛与ATP合酶对ΔpH的消耗有关，ATP合酶在有利于假线性和循环电子传递的条件下仍保持活性。
