Krasnovskiĭ A A, Kovalev Iu V, Kukarskikh G P, Guliaev B A
Biofizika. 1980 Sep-Oct;25(5):821-6.
Spectral parameters, decay time and quantum yield of low temperature (--196 degrees) delayed luminescence of chloroplasts and chloroplasts fragments have been investigated. It has been shown that the fragments enriched in photosystem 2, photosystem 1 of stroma or grana, obtained by differential centrifugation after digitonin treatment produce a delayed emission with components similar to that of initial chloroplasts, normal leaves and alga; i. e. phosphorescence (maximum 960--980 nm) and delayed fluorescence (maxima at 690 and 740 nm) of chlorophyll and phosphorescence of pigments of different nature (780--820 nm). Excitation spectra of chlorophyll phosphorescence have the maximum at 669 +/- 1 nm and shoulder at 650 nm. The quantum yield of chlorophyll phosphorescence in chloroplast is found to be lower than that of chlorophyll in ethanol by the factor of 200. It increases with destruction of initial structures reaching the maximal value in the most light fragments. The data suggest that the luminescence studied accompanies desactivation of the triplet states of the chlorophyll molecules involved in the photosynthetic pigment complex. On the basis of previous studies it has been proposed that the increase of phosphorescence intensity in the light particles is due to disturbances in the pigment complex leading to a decrease of triplet-triplet energy transfer from chlorophyll to carotenoids.
研究了叶绿体和叶绿体片段在低温（-196℃）下延迟发光的光谱参数、衰减时间和量子产率。结果表明，经洋地黄皂苷处理后通过差速离心获得的富含光系统2、基质或基粒光系统1的片段产生的延迟发射，其成分与初始叶绿体、正常叶片和藻类相似；即叶绿素的磷光（最大波长960 - 980nm）和延迟荧光（最大波长690和740nm）以及不同性质色素的磷光（780 - 820nm）。叶绿素磷光的激发光谱在669±1nm处有最大值，在650nm处有肩峰。发现叶绿体中叶绿素磷光的量子产率比乙醇中叶绿素的量子产率低200倍。随着初始结构的破坏，其量子产率增加，在最轻的片段中达到最大值。数据表明，所研究的发光伴随着光合色素复合物中叶绿素分子三重态的失活。根据先前的研究，有人提出轻颗粒中磷光强度的增加是由于色素复合物的紊乱导致三重态-三重态能量从叶绿素向类胡萝卜素的转移减少。
