AtELF3α and AtELF3β oppositely regulate flower induction. A) The AtELF3 genomic region has two TSSs. The 5′ UTRs and coding sequences (exons) are represented by white and black boxes, respectively. Black lines indicate introns. AtELF3α encodes the full-length protein, while AtELF3β encodes the shorter form. B) PCR analysis reveals two TSSs in the AtELF3 genomic region. The cDNA and genomic DNA samples were analyzed using the same primers, as indicated in A). The AtELF3β band (755 bp) was amplified in cDNA samples using primers AtELF3-2F and AtELF3-1R. C) Phenotype of AtELF3α-OE-1, AtELF3α-OE-22, AtELF3β-OE-35, and AtELF3β-OE-44 under long-day conditions (16 h light/8 h dark). D), E) Flowering time (D) and number of rosette leaves (E) at the opening of the first flower shown in C). Data are means ± s.e.m. (n ≥ 22). Different letters indicate significant differences (P < 0.05), as determined using Duncan's multiple range test. Scale bar, 1 cm. F) Phenotype of transgenic Arabidopsis lines co-expressing AtELF3β and AtELF3α. G), H) Flowering time (G) and number of rosette leaves (H) at the opening of the first flower. Plants were grown in long-day conditions (16 h light/8 h dark). Data are means ± s.e.m. (n ≥ 14). Different letters indicate significant differences (P < 0.05), as determined using Duncan's multiple range test.