Krieger-Liszkay A, Kienzler K, Johnson G N
Institute of Biology II, University of Freiburg, Germany.
FEBS Lett. 2000 Dec 15;486(3):191-4. doi: 10.1016/s0014-5793(00)02250-x.
Photoinhibition of photosystem II (PS II) activity was studied in thylakoid membranes illuminated in the presence of the inhibitor of the cytochrome b(6)f complex 2'iodo-6-isopropyl-3-methyl-2',4, 4'-trinitrodiphenylether (DNP-INT). DNP-INT was found to decrease photoinhibition. In the absence of DNP-INT, anaerobosis, superoxide dismutase and catalase protected against photoinhibition. No effect of these treatments was observed in the presence of DNP-INT. These data demonstrate that photoinhibition under these conditions is caused by reactive oxygen species which are formed most probably by the reduction of oxygen at photosystem I. The results are discussed in terms of the importance of photosynthetic control in protection against photoinhibition in vivo.
在细胞色素b(6)f复合物抑制剂2'-碘-6-异丙基-3-甲基-2',4,4'-三硝基二苯醚（DNP-INT）存在的情况下，对类囊体膜中光系统II（PS II）活性的光抑制进行了研究。发现DNP-INT可降低光抑制。在没有DNP-INT的情况下，无氧状态、超氧化物歧化酶和过氧化氢酶可防止光抑制。在DNP-INT存在的情况下，未观察到这些处理的效果。这些数据表明，在这些条件下的光抑制是由活性氧引起的，活性氧很可能是由光系统I处的氧还原形成的。根据光合控制在体内防止光抑制中的重要性对结果进行了讨论。
