Vass Imre, Cser Krisztian
Institute of Plant Biology, Biological Research Center, Szeged, Hungary.
Trends Plant Sci. 2009 Apr;14(4):200-5. doi: 10.1016/j.tplants.2009.01.009. Epub 2009 Mar 18.
Light-induced damage of the photosynthetic apparatus in plants is an important phenomenon that primarily affects the photosystem II complex. Here, we propose a new model of photoinhibition in which charge recombination processes have a double-faced role: first, photodamage is induced by singlet oxygen, which is produced via interaction with the triplet reaction center chlorophyll ((3)P(680)) arising from the recombination of the charge-separated state between P(680) and the pheophytin electron acceptor ((3)[P(680)(+)Phe(-)]). Second, photoprotection is provided by competition between (3)[P(680)(+)Phe(-)] formation and direct recombination of the (1)[P(680)(+)Phe(-)] and P(680)(+)Q(A)(-) states. The efficiency of these two pathways is under control of the redox potential of the Phe and Q(A) electron acceptors, which is utilized during adaptation to high light conditions.
光诱导的植物光合机构损伤是一种重要现象,主要影响光系统II复合体。在此,我们提出一种新的光抑制模型,其中电荷复合过程具有双重作用:首先,单线态氧诱导光损伤,单线态氧通过与电荷分离态(P(680)与脱镁叶绿素电子受体((3)[P(680)(+)Phe(-)])之间的重组产生的三重态反应中心叶绿素((3)P(680))相互作用而产生。其次,(3)[P(680)(+)Phe(-)]形成与(1)[P(680)(+)Phe(-)]和P(680)(+)Q(A)(-)态的直接重组之间的竞争提供了光保护作用。这两条途径的效率受脱镁叶绿素和Q(A)电子受体氧化还原电位的控制,在适应高光条件期间发挥作用。