Fig. 7
BBX22IR positively regulates photomorphogenic development. a, b Images and bar graphs of hypocotyl lengths for wild-type (WT) and 3 independent 35S::HA-BBX22IR transgenic lines grown under dark (black bars) or continuous white light (10 μmole/ m−2 s−1) (orange bars) for 4 days (a), and WT, bbx22 mutant and 3 independent bbx22 HA-BBX22IR lines under dark (black bars) or short-day condition (8-h 100 μmole/ m−2 s−1 white light and 16-h dark) (orange bars) for 4 days (b). The representative results from 3 biological replicates are shown. Data are mean ± SEM. * p < 0.001 (Student’s t test). Scale bar, 5 mm. c BBX22IR dimer formation by yeast two-hybrid assay. d Detection of BBX22 and BBX22IR proteins in 4-day-old etiolated Arabidopsis seedlings treated with 0, 4, 8, 12, 16, or 24 h of 75 μmole/ m−2 s−1 white light. The immunoblot was performed with anti-HA antiserum (upper panel) and anti-α tubulin antiserum (bottom panel) as loading controls. Asterisks indicate the non-specific bands. Arrowheads mark HA-BBX22, HA-BBX22 truncated, and HA-BBX22IR. e Model illustrates the biological function of BBX22IR in photomorphogenic development