May promote auxin-stimulated organ elongation, such as hypocotyls, stamen filaments and petals. Localizes in a punctate pattern at the plasma membrane. Expressed in hypocotyls, cotyledons, petioles, young rosette leaves, apical portion of inflorescence stems, stamen filaments and petals. Plants over-expressing SAUR63 display elongated hypocotyls, twisted inflorescence stems, and increased length of stamen filaments and petals. Belongs to the ARG7 family. Truncated N-terminus.