Picosecond studies at 77 K of energy transfer in chloroplasts at low and high excitation intensities
Picosecond studies at 77 K of energy transfer in chloroplasts at low and high excitation intensities
复制标题
77 K 皮秒研究低和高激发强度下叶绿体中的能量转移
DOI：
10.1016/0005-2728(85)90085-4
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
J. Breton
中科院分区：
文献类型：
--
作者：
B. Wittmershaus;T. Nordlund;W. Knox;R. Knox;N. Geacintov;J. Breton
Spinach chloroplast chlorophyll fluorescence at 685 and 735 nm (F685andF735) has been time-resolved with a low-jitter streak camera system. Measurements are reported largely for 77 K, using single 30-ps 532-nm excitation pulses with pulse fluences of 2 · 1012to 2 · 1016photons · cm−2. A slightly fluence-dependent delay (16 ± 3 ps) found for the rise ofF735relative toF685is too small to correspond to transfer into the species emittingF735from the species emittingF685. The rise ofF735is biphasic at lower intensities and monophasic at higher intensity. The delay in the rise ofF685is smaller than approx. 2 ps. The time-resolvedF685is fit with a three-component model in which energy is transferred from a large pool of antenna chlorophylls to a small pool closely connected to the reaction center, all exciton annihilation occurring in the small pool. TheF735biphasic rise and its sensitivity to excitation fluence is explained by a similar but independent model. Data at our lowest intensities are consistent with those obtained by a photon-counting method using very low intensity excitation.
