Seasonal changes in photosystem II organisation and pigment composition in Pinus sylvestris
Seasonal changes in photosystem II organisation and pigment composition in Pinus sylvestris
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DOI：
10.1007/bf00239954
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发表时间：
1995-08
期刊：
影响因子：
4.3
通讯作者：
C. Ottander;D. Campbell;G. Öquist
中科院分区：
文献类型：
--
作者：
C. Ottander;D. Campbell;G. Öquist
针叶树的北方地带遇到相当大的低温和强光在冬季，当光合作用消耗的激发能被阻止的联合应力。常绿樟子松Pinus sylvestris L.这些压力与光系统II（PSII）组织和色素组成的主要季节性变化相吻合。最早的变化发生在9月，在任何冻结应力之前，与初始损失的叶绿素，D1-蛋白的PSII反应中心和PSII捕光复合物（LHC II）蛋白。在10月有一个短暂的增加F0，由于反应中心失去了D1的光捕获天线的分离。D1-蛋白质含量最终下降到90%，12月达到最低值，但PSII光化学效率[可变荧光（Fv）/最大荧光（Fm）]没有达到冬季最低值，直到2月中旬。类胡萝卜素的组成季节性变化，叶黄素和类胡萝卜素的叶黄素循环在冬季增加了一倍，而叶黄素的环氧化状态从0.9下降到0.1，从10月至1月。叶绿素的损失是完整的10月，在冬季大部分剩余的叶绿素重组在特定的多肽组合物，这显然有效地淬火激发能量通过非辐射耗散的聚集。秋季和冬季变化的时间表明，叶黄素脱环氧化与冬季猝灭的叶绿素荧光，而光化学效率的下降涉及更多的D1-蛋白的损失。在4月和5月恢复PSII的光化学，蛋白质合成，色素重排和玉米黄质环氧化伴随发生。室内恢复光合作用在冬季强调的分支机构在有利的条件下完成3天内，快速增加F0，环氧化状态的叶黄素和捕光多肽，其次是恢复D1-蛋白质含量和Fv/Fm，所有没有净增加叶绿素。秋季和冬季的重组允许樟子松保持大量的叶绿素在淬火，光保护状态，允许光合作用在春季迅速恢复。
Conifers of the boreal zone encounter considerable combined stress of low temperature and high light during winter, when photosynthetic consumption of excitation energy is blocked. In the evergreenPinus sylvestrisL. these stresses coincided with major seasonal changes in photosystem II (PSII) organisation and pigment composition. The earliest changes occurred in September, before any freezing stress, with initial losses of chlorophyll, the D1-protein of the PSII reaction centre and of PSII light-harvesting-complex (LHC II) proteins. In October there was a transient increase in F0, resulting from detachment of the light-harvesting antennae as reaction centres lost D1. The D1-protein content eventually decreased to 90%, reaching a minimum by December, but PSII photochemical efficiency [variable fluorescence (Fv)/maximum fluorescence (Fm)] did not reach the winter minimum until mid-February. The carotenoid composition varied seasonally with a twofold increase in lutein and the carotenoids of the xanthophyll cycle during winter, while the epoxidation state of the xanthophylls decreased from 0.9 to 0.1 from October to January. The loss of chlorophyll was complete by October and during winter much of the remaining chlorophyll was reorganised in aggregates of specific polypeptide composition, which apparently efficiently quench excitation energy through non-radiative dissipation. The timing of the autumn and winter changes indicated that xanthophyll de-epoxidation correlates with winter quenching of chlorophyll fluorescence while the drop in photochemical efficiency relates more to loss of D1-protein. In April and May recovery of the photochemistry of PSII, protein synthesis, pigment rearrangements and zeaxanthin epoxidation occurred concomitantly. Indoor recovery of photosynthesis in winter-stressed branches under favourable conditions was completed within 3 d, with rapid increases in F0, the epoxidation state of the xanthophylls and in light-harvesting polypeptides, followed by recovery of D1-protein content and Fv/Fm, all without net increase in chlorophyll. The fall and winter reorganisation allowPinus sylvestristo maintain a large stock of chlorophyll in a quenched, photoprotected state, allowing rapid recovery of photosynthesis in spring.