THE EFFECTS OF DESICCATION ON EXCITATION-ENERGY TRANSFER AT PHYSIOLOGICAL TEMPERATURES BETWEEN THE 2 PHOTOSYSTEMS OF THE RED ALGA PORPHYRA-PERFORATA
THE EFFECTS OF DESICCATION ON EXCITATION-ENERGY TRANSFER AT PHYSIOLOGICAL TEMPERATURES BETWEEN THE 2 PHOTOSYSTEMS OF THE RED ALGA PORPHYRA-PERFORATA
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DOI：
10.1016/s0044-328x(81)80100-6
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发表时间：
1981-01-01
期刊：
影响因子：
--
通讯作者：
OQUIST, G
中科院分区：
文献类型：
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作者：
FORK, DC;OQUIST, G
测定了红色多孔藻湿菌体和干菌体的室温荧光发射和激发光谱。在黑暗中干燥的紫菜的光系统[PS] II陷阱关闭效率降低，PSII荧光发射在687 nm处的减少和伴随的远红PSI荧光发射带的增加。紫菜通过产生从PSII的藻红蛋白到PSI的激发能分布的强烈增加来响应干燥，最初转移到PSI并在溢出中增加的光的部分或两者。没有PSII陷阱关闭发生在室温下，在强光下干燥的紫菜，表明PSII陷阱在这些条件下关闭。与深色干燥的紫菜相比，浅色干燥的紫菜具有687 nm荧光带的完全损失。687 nm波段的这种损失伴随着737 nm波段的成比例损失。在光照干燥条件下，紫菜Fo不受影响，只有部分Fv被去除。显然，PSII中反应中心的荧光猝灭可以解释这一点。增加能量转移到PSI在干燥状态下可能会保护更多的光不稳定的反应中心的PSII从光化学损伤时，这些植物受到干燥和高光强。
Room temperature fluorescence emission and excitation spectra were measured for wet and desiccated thalli of the red alga P. perforata. Porphyra that were desiccated in the dark had a reduced efficiency of photosystem [PS] II trap closure with a decrease of the PSII fluorescence emission at 687 nm and a concomitant increase of the far red PSI fluorescence emission band. Porphyra responds to desiccation by producing a strong increase in the distribution of excitation energy from phycoerythrin of PSII to PSI that may be mediated by increases in .alpha., the fraction of light that is transferred initially to PSI and increases in spillover or both. No PSII trap closure occurred at room temperature in Porphyra that was dried in strong light, indicating that the PSII traps were closed under these conditions. Light dried Porphyra had a complete loss of the 687 nm fluorescence band compared to dark dried Porphyra. This loss of the 687 nm band was accompanied by a proportionate loss of the 737 nm band. In light dried Porphyra Fo is not affected, only part of Fv was eliminated. Apparently, reaction center quenching of fluorescence in PSII may account for this. Increased energy transfer to PSI in the desiccated state may protect the more photolabile reaction centers of PSII from photochemical damage when these plants are subjected to desiccation and high light intensities.