Effects of BR application to wild-type Col (WT), dnd1, bin2-1, and bri1-301 plants on SAUR-AC1 expression. The expression of SAUR-AC1 in the absence of exogenous BR relative to the level in wild-type plants was 0.91, 0.86, and 0.70 in dnd1, bin2-1, and bri1-301 plants, respectively.