Deletion of the 2nd intron of AtELF3 results in AtELF3β downregulation and late flowering in Arabidopsis. A) Schematic diagram of the AtELF3 locus in the two AtELF3 CRISPR lines. The annotated AtELF3 gene structure is shown at the top; exons are marked as squares and introns as straight lines. The edited AtELF3-Δ60 and AtELF3-Δ53 lines are represented in the middle and bottom, respectively. Close-ups provide detailed information on the positions of the deletions as determined by Sanger sequencing of the CRISPR lines, aligned to the wild-type AtELF3 genomic sequence. B) Identification of the mutant site in AtELF3-Δ60 and AtELF3-Δ53 lines by PCR. C), D) Transcript level of AtELF3α(C) and AtELF3β(D) in AtELF3-Δ60 and AtELF3-Δ53 lines. Data are means ± s.e.m. (n = 5). Different letters indicate significant differences (P < 0.05), as determined using Duncan's multiple range test. E) Flowering time phenotypes of the nontransformed control plants (Col-0), AtELF3-Δ60, and AtELF3-Δ53 lines under long-day conditions (16 h light/8 h dark). Scale bar, 1 cm. F), G) Flowering time (F) and number of rosette leaves (G) at the opening of the first flower in plants grown under long-day conditions (16 h light/8 h dark). Data are means ± s.e.m. (n ≥ 22). Different letters indicate significant differences (P < 0.05), as determined using Duncan's multiple range test.