Schematic illustration of the IRX genes and T-DNA insertions for the irx mutants. (A) irx9-2 in At2g37090 (IRX9) is located in the coding region of an exon. (B) irx8-6 in At5g54690 (IRX8) is located in an intron. (C) irx7 in At2g28110 (IRX7) is located in a non-coding region of an exon. T-DNAs are indicated with triangles.