Auxin signalling: the beginning, the middle and the end

The plant hormone auxin is central to the regulation of growth and developm ent. Recent work has demonstrated that auxin signalling depends on targeted protein degradation, and in the past year this model has been strengthened . The focus is now on identifying the targets of this degradative pathway, determining how auxin influences the degradative process and linking the tu rnover of specific proteins to the numerous downstream responses to auxin.