Encodes ARL, a gene similar to ARGOS involved in cell expansion-dependent organ growth. Upregulated by brassinosteroid. Acts downstream of BRI1. The mRNA is cell-to-cell mobile.
Present throughout the cotyledons as well as in the mature regions of roots in young seedlings. Expressed in expanding leaves, but not in leaf primordia and juvenile leaves. In flowers, accumulates in sepals and stamen filaments, as well as at the apices and bases of siliques.