Characterization of an additional YHB allele. A, Morphology of seedlings grown under 30 μmol m−2 s−1 white light in 12:12 L/D cycles. Wild-type (Col-0) and Col-0 seedlings transformed with a PHYB::PHYB-Y276H construct (YHB) were grown on Murashige and Skoog (MS) medium for 6 d. B, Quantification of hypocotyl lengths of Col-0, YHB (Col-0), Ler, and YHB (Ler) seedlings grown as described in (A). Previously described Ler seedlings similarly transformed with YHB are presented for comparison (Su and Lagarias, 2007). sem is presented, n > 20. *, Significant difference for the indicated comparison (P < 0.001, Student’s t test). C, Immunoblot analysis of phyB/YHB protein levels showing relative phyB accumulation in Col-0 and YHB (Col-0) seedlings. Ler wild type and various transgenic plants harboring the Ler YHB transgenic allele derived from YHB/phyA201phyB-5 line #5 (Su and Lagarias, 2007) are presented for comparison.