Recovery of photoinactivated photosystem II in leaves: retardation due to restricted mobility of photosystem II in the thylakoid membrane
Recovery of photoinactivated photosystem II in leaves: retardation due to restricted mobility of photosystem II in the thylakoid membrane
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DOI：
10.1007/s11120-008-9363-5
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发表时间：
2008-09
影响因子：
3.7
通讯作者：
R. Oguchi;Husen Jia;J. Barber;W. Chow
中科院分区：
文献类型：
--
作者：
R. Oguchi;Husen Jia;J. Barber;W. Chow
利用fv /Fm、暗适应状态下叶绿素荧光变值与最大荧光值之比以及PS II的最佳光化学效率指标，对低温强光预处理后叶片II光系统（PS II）的功能进行了监测。(1)水分胁迫和(2)弱光和低温条件下，菠菜和大根苜蓿中PS II功能的恢复均受到(1)水分胁迫和(2)弱光生长的阻碍。在菠菜叶段中，水分胁迫本身既不影响fv / fnor，也不影响远红光激活三磷酸腺苷（ATP）合成酶合成ATP的能力，但通过扫描电镜观察，在冷冻和断裂样品中，水分胁迫诱导叶绿体收缩。水分胁迫和LL植物生长的一个共同特征是PS II复合物的锚定增强，要么在水分胁迫条件下穿过缩小的管腔，要么在LL生长的大颗粒中穿过隔墙间隙。我们认为，这种增强的锚定限制了类囊体膜系统中PS II复合物的移动性，从而阻碍了光灭活的PS II反应中心向基质核糖体的侧向迁移以进行修复。
The functionality of photosystem II (PS II) following high-light pre-treatment of leaf segments at a chilling temperature was monitored asFv/Fm, the ratio of variable to maximum chlorophyll fluorescence in the dark-adapted state and a measure of the optimal photochemical efficiency in PS II. Recovery of PS II functionality in low light (LL) and at a favourable temperature was retarded by (1) water stress and (2) growth in LL, in both spinach andAlocasia macrorrhizaL. In spinach leaf segments, water stress per se affected neitherFv/Fmnor the ability of the adenosine triphosphate (ATP) synthase to be activated by far-red light for ATP synthesis, but it induced chloroplast shrinkage as observed in frozen and fractured samples by scanning electron microscopy. A common feature of water stress and growth of plants in LL is the enhanced anchoring of PS II complexes, either across the shrunken lumen in water-stress conditions or across the partition gap in larger grana due to growth in LL. We suggest that such enhanced anchoring restricts the mobility of PS II complexes in the thylakoid membrane system, and hence hinders the lateral migration of photoinactivated PS II reaction centres to the stroma-located ribosomes for repair.