a–r, Over-night treatment with water, 50 μM 2,4-D or tZ. pARR7m (e, k, q) pARR15m (f, l, r) explained in (u). Filled arrowheads denote bc, open arrowheads qc. s, In situ hybridisation to ARR7 mRNA. t, ARR7 and ARR15 mRNA induction assayed by qRT-PCR after 4-hour treatment of embryos with 1 μM tZ or 2,4-D. u, ARR7 and ARR15 promoters. TGTC on sense and antisense strands as blue bars. Red asterisks: TGTC -> TGgC. Grey shade connects conserved regions; see text for detail.