Abstract
Photosystem I is a chlorophyll protein complex, which is consist of 14 subunits and mediates the electron transfer from plastocyanin to ferredoxin. PsaH is one of the subunits of photosystem I and has been proposed to be required for state transitions. However, the molecular mechanism of its contribution to state transitions has not been clarified. In the present study, we generated knock down transformants of PsaH by means of RNAi technique from a green alga Chlamydomonas reinhardtii. After screening of 15 paromomycin-resistant transformants, we obtained 2 lines of transformant in which the accumulation of PsaH protein decreased to approximately 20% of that in wild-type cells. We are now analyzing the state transitions of these transformants by means of low temperature fluorescence spectra and will discuss the role of PsaH on the association of minor LHCII proteins with photosystem I.
