Seasonal changes of excitation energy transfer and thylakoid stacking in the evergreen tree Taxus cuspidata:: How does it divert excess energy from photosynthetic reaction center?
Seasonal changes of excitation energy transfer and thylakoid stacking in the evergreen tree Taxus cuspidata:: How does it divert excess energy from photosynthetic reaction center?
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DOI：
10.1016/j.bbabio.2008.01.008
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发表时间：
2008-04-01
影响因子：
4.3
通讯作者：
Tanaka, Ayumi
中科院分区：
文献类型：
--
作者：
Yokono, Makio;Akimoto, Seiji;Tanaka, Ayumi
光系统必须有效地消散吸收的光能在冻结条件下。为了阐明能量耗散机制，我们研究了万年青植物东北红豆杉针叶的能量传递和耗散动态的时间分辨荧光光谱。夏秋两季的能量传递过程与其它高等植物相似。然而，在冬季针叶，荧光寿命变短，不仅在PSII，但也在PSI，表明能量耗散在冬季针叶。此外，在不同的激发波长下得到了几乎相同的荧光光谱。与此相反，荧光光谱显示出很大的差异，由于激发波长在弹簧针。春季针叶在550 nm激发下的荧光光谱与冬季针叶相似，但在叶绿素激发下未观察到红色叶绿素荧光。这些观察结果表明，一些复合物与某种红移类胡萝卜素和红色叶绿素解链的核心复合物在春季。激发能动态的季节性变化也讨论了类囊体堆积的变化。(C)2008 Elsevier B.V.保留所有权利。
Photosystems must efficiently dissipate absorbed light energy under freezing conditions. To clarify the energy dissipation mechanisms, we examined energy transfer and dissipation dynamics in needles of the evergreen plant Taxus cuspidata by time-resolved fluorescence spectroscopy. In summer and autumn, the energy transfer processes were similar to those reported in other higher plants. However, in winter needles, fluorescence lifetimes became shorter not only in PSII but also in PSI, indicating energy dissipation in winter needles. In addition, almost the same fluorescence spectra were obtained with different excitation wavelengths. In contrast, the fluorescence spectrum showed a large difference due to excitation wavelength in spring needles. The fluorescence spectrum of spring needles in 550-nm excitation showed similar spectra to that of winter needles, however, red-chlorophyll fluorescence was not observed in chlorophyll excitation. These observations suggest that some complexes with some kind of red-shifted carotenoid and red-chlorophyll unlink from the core complex in spring. Seasonal changes of excitation energy dynamics are also discussed in relation to changes in thylakoid stacking. (C) 2008 Elsevier B.V. All rights reserved.