OVER-EXPRESSION OF A C-TERMINAL REGION OF PHYTOCHROME-B

In an attempt to identify domains directly involved in the signal tran sduction of phytochrome B (phyB), we over-expressed the achromophoric C-terminal half of phyB under control of the CaMV-35S promoter in tran sgenic Arabidopsis. In three independent transgenic lines, we detected accumulation of the introduced protein of predicted size at levels hi gher than that of the endogenous phyB by immunoblot analysis. Although these transgenic plants did not show any phenotype in the dark, enhan cement of the phyB-dependent inhibition of hypocotyl elongation and re duction of the phytochrome A (phyA)-dependent inhibition were observed .