Plant signaling: Interplay of brassinosteroids and auxin in root meristems

The plant hormones brassinosteroids (BRs) and auxin interact to regulate root meristem size. A new study reveals dual and opposing roles for BRs in auxin biosynthesis and signaling output in the Arabidopsis root epidermis, demonstrating that epidermis-derived BR signaling is required for root meristem maintenance through its effect on auxin signaling.