Figure 5.

Phenotypic Analysis of Other Light-Grown Y^GAF Mutants of Phytochrome B Reveals Both Gain-of-Function and Loss-of-Function Phenotypes.

(A) Transgenic plants expressing PHYB^Y276I, PHYB^Y276Q, and PHYB^Y276R mutant alleles of PHYB in the phyA phyB double mutant were grown on sucrose-free media for 6 d under 20 μmol m⁻² s⁻¹ of continuous R irradiation. One representative line from each transformation is shown.

(B) Immunoblot analysis of PHYB protein levels was performed as in Figure 1.

(C) Transgenic plants expressing Y276H, Y276I, Y276Q, and Y276R alleles of PHYB were grown for 5 weeks under continuous white light (W) at the fluence rate of 50 μmol m⁻² s⁻¹.