Evolutionary aspects of auxin signalling

Abstract

Auxin is one of the first phytohormones to be discovered in plants. It plays a key role in plant growth and development and in the evolution of land plants. The presence of auxin has been reported from microalgae to higher seed plants. However, tracing the origin of auxin response and of the associated proteins has proven to be more difficult. This chapter will summarize recent molecular developments on the origin of auxin metabolism, transport and signalling in green, red and brown algae, mosses and spikemosses.