Figure 8.

VRN1, VRN2, and FT expression in the fourth leaf of ABR6 and Bd21 after varying periods of cold treatment. Seeds were imbibed with water and not vernalized or vernalized for 2, 4, or 6 weeks and transferred to a growth chamber with parameters similar to environment 2. Fully expanded fourth leaves were harvested in the middle of the photoperiod. Relative gene expression of VRN1 (A), VRN2 (B), and FT (C) was determined using reverse transcription-quantitative PCR and analyzed using the 2^−ΔΔCt method. All genes were normalized to 1 based on Bd21 expression with no cold treatment (0 weeks), and UBIQUITIN-CONJUGATING ENZYME18 was used as an internal control. Bars represent means of three biological replicates, with error bars showing 1 se. Different letters represent statistically significant differences based on pairwise Student’s t tests using a multiple hypothesis-corrected P value threshold of 0.05 with the Benjamini-Hochberg approach (Benjamini and Hochberg, 1995).