摘要
光合作用的核心问题之一是光合作用的原初反应，即光能的高效吸收、传递和转化的机理。本研究采用飞秒吸收技术，通过以４００ｎｍ激发，５２０～７００ｎｍ连续探测，对ＰＳⅡ颗粒及核心复合物中的能量传递、电荷分离等过程进行了研究。在ＰＳⅡ颗粒中，得到的０．１６ｐｓ，２．８ｐｓ和２０．９ｐｓ等过程为在光系统Ⅱ捕光天线复合物（ＬＨＣⅡ）中的能量传递过程，而８．６ｐｓ过程为由ＬＨＣⅡ向ＰＳⅡ核心和反应中心的能量传递过程。在ＰＳⅡ核心复合物中，得到的０．３５ｐｓ和１１．２ｐｓ过程与ＰＳⅡ内周天线之间的能量传递过程有关，而２．９ｐｓ和２０．１ｐｓ过程可能为电荷分离过程或与ＰＳⅡ反应中心有关的能量传递过程。
The energy transfer and charge separation in the isolated PSⅡ particles and core complexes from spinach were studied with femtosecond absorption spectroscopy by exciting the PSⅡ particles and core complexes directly at 400 nm and probing them in the wavelength range of 520 to 700 nm with 200 fs resolution. The results from PSⅡ particle excitation showed that the processes of 0.16 ps, 2.8 ps and 20.9 ps components obtained by global analysis of data were the energy transfers occurred in the light_harvesting complexes Ⅱ (LHCⅡ). The process of 8.6 ps component was the energy transfer from LHCⅡ to PSⅡ core and finally to the reaction center. The other result from PSⅡ core comple excitation showed that the 0.35 ps and 11.2 ps components attributed to the energy transfer among the internal antennae. It was concluded that the 2.9 ps and 20.1 ps components could be attributed to the charge separation processes or the energy transfer processes between core antennae and reaction center.
关键词
飞秒吸收光谱
原初反应
能量传递过程
光系统Ⅱ
Femtosecond absorption spectroscopy, Primary processes, Energy transfer, Photosystem Ⅱ
