BRC1, HB21, HB40, and HB53 regulate the expression of ABA-related genes encoding TFs. (A and B) mRNA levels of ABF3, AFP3, GBF3, and NAP analyzed by quantitative PCR in axillary buds in wild-type and hb21 hb40 hb53-1 buds treated with W or W+FR light for 8 h (A) or in wild-type buds after an application of 50 µM ABA for 8 h (B). (C and D) Expression of ABF3 (C) and NAP (D) in 7-d-old GUSind, HA:BRC1ind, HA:HB21ind, HA:HB40ind, and HA:HB53ind seedlings treated for 8 h with 10 µM estradiol. Error bars show the SEM of three biological replicates. Asterisks indicate significant differences (P < 0.05; student’s t-test) between control and treated plants. Letters denote significant differences (P < 0.05; one-way ANOVA) among means.