Abstract
The extrinsic proteins present in the luminal space of thylakoids are shown to play crucial roles in optimizing the water-oxidizing activity in photosystem II (PSII). In higher plants, PsbO, PsbP and PsbQ proteins are the major components of luminal extrinsic proteins, and they have been extensively analyzed from biochemical and structural standpoints in the past decades. However, their physiological functions in vivo have been poorly understood. In this study, we have applied the RNA interference (RNAi) technology to generate transgenic tobacco plants, psbOir, psbPir and psbQir, in which the expression of psbO, psbP and psbQ genes was selectively and significantly silenced. Both psbOir and psbPir plant displayed distinct phenotypes such as drastic reduction in the growth rate and pale green-colored leaves. On the other hands, there was no obvious visible difference between the psbQir and the wild-type plants. Further analyses about these RNAi tobacco plants are on going.
