Host: The Japanese Society of Plant Physiologists
Pages 0044
Photosystem I(PS I) pigment-protein super complex of diatoms consists of two peripheral antennas, FCP(fucoxanthin-Chlorophyll(Chl)-binding proteins) I-1, FCP I-2, and core complex (PS I-Core). We studied the ultra-fast excitation energy transfer in isolated FCP-PS I super-complex, PS I-Core complex, FCP I-1 and FCP I-2 isolated from C. gracillis by the upconversion and the streak camera methods at 17 K. Results of a global analysis revealed a major fluorescence decay phase with a 5-ps time constant upon the selective excitation of Chl a at 430 nm. However, it was not observed upon the 460-nm excitation that mainly excited Chl c in FCP. Thus, the 5-ps phase was interpreted as the energy trapping in the core. Two components with 0.86-ps and 14-ps time constants were observed upon the excitation at 460 nm suggesting the two energy-transfer pathways from FCP to the core (FCP I-1-> core and FCP I-2-> core).
