| "Photosynthesis is the most important chemical reaction on earth". It is the process in green plants and certain other organisms by which carbohydrates are synthesized from carbon dioxide and water using light as an energy source; oxygen is released at the same time. It has close relationship with food, energy and ecological environment, which is essential to human. It is a compelling field.The work of this dissertation is supported by a sub-subject of "photosynthesis high efficiency light energy transform mechanism and its application in agriculture", which is the State key Basic Research Development Plant of P. R. China (973). The aim of this plan is to provide academic prove of increasing the efficiency of photosynthesis.In dissertation , the study on structure of PS II and excitation energy transfer of its pigments in international is summarized. Moreover, two series of instruments: steady/transient fluorescence spectroscopy and transient difference absorption spectroscopy assembled by us is introduced simply. We analyse the ultrafast energy transfer process of PS II particle complex, core complex and light -harvesting complex(LHC II) with this two series spectroscopes comprehensively . Below are the main results of the dissertation:1. Excited with different wavelengths, though the pigments accepting energy at the first time was various, they all take role in the energy transfer process, and the energy was transferred to lowest excitation state of Chla molecule.2. Analysing fluorescence emission spectra with Gauss-fitting, we found there were several characteristic Chl molecules in the photosystem II particle complex :Chlb639 640 (Chla/ba e : a represents the peak of absorption , e represents the peak ofemission) , Chlb,Chla, Chla Chla/b Chla,Chla , ChlaChla Chla .While in core antennae CP43,there are following :Chla ,Chl Chl and Chla and CP47: Chla ,Chla Chla Chla and Chla ; RC: Chla Chla , Chla Chla,Chla and Chla3. Research core complex at three different temperatures :20,42and 48 by transient fluorescence spectroscopy, we found reaction centre had been destroyed at 48,however ,core antennae CP 43 and CP 47 is still functional .4. When we fitted the decay curve of fluorescence emission, the following conclusion were achieved : Car in LHCII transfer energy to Chla molecule withinl6.6 ps, and then transfer energy to reaction centre by Chla ,the whole process happened in the time range of 217-249 ps. While Chla in LHC II transfer energy to reaction centre just need 30-40 ps . P -Car in core antennae complex transfer its energy to reaction center in 85-183 ps . And the component of 201ps-18.13ns reflects the progress of charge recombination of primary pair.5. There were three time components of energy transfer in LHC II trimmer :747fs, 3.28ps, 32.1ps . 747fs lifetime component is assigned to Chlb649 to Chla 665 energy transfer via Chlb657.3.28ps reflect energy transfer from Chla 677 to Chla absorbing longer wavelength. 32.15ps related to equilibrium between monomers of trimmer.The innovation of the dissertation are listed below:1. Use white light as probe pulse of transient difference absorption technology; it's the first time in the country. It will be significative for our studying the mechanism of photosynthesis in the future.2. Combined spectroscope made in England and laser source of American with tuning delay system and ultra-high-speed PIN detector, we obtained excellent steady /transient fluorescence spectroscopy.3. Analysing the fluorescence emission fitting by Guess-fitting, we obtained 11 kinds of characteristic Chl molecules in photosystem II particle complex and core complex, among these Chl molecules, four kinds of Chi belongs to CP 43,five belong to Cp 47 and six belong to reaction centre.4. Many data ,such as intact curve of integrated spectra ,Guess spectra and lifetime of energy transfer in photosystem II particle complex were obtained at different temperature, it provided important proves for study the character ,structure and energy transfer mechanism o...
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