Abstract
Whereas light energy absorbed in photosystem II (PSII) is used for photosynthetic electron transfer and carbon dioxide fixation, the excess proportion of absorbed energy is dissipated as heat. This thermal dissipation, which can be detected as non-photochemical quenching (NPQ) in chlorophyll fluorescence, is controlled by PsbS. To reveal the quantitative relation between the electron transport activity and NPQ formation, we produced the psbS-silenced rice using RNA interference.
When we divided the fate of absorbed light energy in PSII to electron transport (P), dissipation in antenna (D) and that at PSII reaction center (E) according to Damming Adams et al (1996), RNAi transformations showed the decrease in (D) with the increase in (E), and the similar level in (P) in comparison with the wild type. These results suggest that NPQ do not down regulate the electron transport activities at PSII of rice.
