抄録
In the previous study, we found that the protein level of phyC in etiolated seedlings is extremely reduced in phyB mutants. In this study, we want to understand the molecular mechanism which controls the phyC level in relation to the phyB. Rice phyAphyB double mutants have reduced level of phyC protein and the etiolated seedlings do not respond to red or far-red light. Overexpression of PHYC gene did not make any differences in the phyAphyB seedlings for their light responses. However, when mutated PHYB gene which lacks a chromophore binding site was expressed, phyC protein amount was recovered to the wild-type level and the transgenic phyAphyB seedlings exhibited distinct responses to red and far-red light, suggesting that the restored phyC is biologically active. These results suggest that phyB protein is indispensable for the stability and therefore, function of phyC in rice photomorphogenesis, probably via the formation of phyB/phyC heterodimer.
