Fig. 7.

PHYB is required for photoperiodic regulation of the CBF pathway and freezing tolerance. WT and phyB plants were grown under SD or LD conditions and tested for gene expression and freezing tolerance. (A) Relative transcript levels for CBF2 were determined at the indicated times. (B) Relative expression levels of the indicated genes were determined at ZT8. (C) Plant freezing tolerance was determined using the electrolyte leakage assay. The results in each test are mean values from three independent experiments (error bars indicate SEM).