植物光合机构的状态转换

植物光合机构的状态转换是一种通过光系统Ⅱ的捕光天线色素蛋白复合体（LHCⅡ）的可逆磷酸化调节激发能在两个光系统间的分配来适应环境中光质等短期变化的机制．一般植物光合机构的LHCⅡ磷酸化主要受电子递体质醌和细胞色素b6f复合体氧化还原状态的调节，从而影响其在两种光系统间的移动。植物光合机构的状态转换也可以通过两种光系统相互接近导致激发能满溢来平衡两个光系统的激发能分配。外界离子浓度骤变可以引起盐藻LHCⅡ磷酸化，其调节过程与电子递体的氧化还原状态无关。绿藻的状态转换可以调节细胞内的ATP供求关系。

State Transition of the Photosynthetic Apparatus in Plant

State transition of the photosyntheticapparatus in plants is a short-term adaptation me-diated mainly by the reversible phosphorylationof the main light-harvesting complex protein(LHCII) and its migration between photosystem I(PSI) and photosystem II (PSII). In higher plantsand Chlamydomonas, LHCII phosphorylation ismainly controlled by the redox state of plasto-quinone pool and cytochrome b6 f complex, whilesalt could induce a redox-independent LHCII phos-phorylation via transient changes in ion concen-trations in Dunaliella. State transition can balancethe distribution of excitation energy between PSIIand PSI by changes in light absorption cross sec-tion and excitation energy spillover between thetwo photosystems. The preliminary results got inthe studies of green algae reveal that state transi-tion can also balance the ATP supply and demand.