CONTROL OF INFLORESCENCE ARCHITECTURE IN ANTIRRHINUM

Flowering plants exhibit two types of inflorescence architecture: dete rminate and indeterminate. The centroradialis mutation causes the norm ally indeterminate inflorescence of Antirrhinum to terminate in a flow er. We show that centroradialis is expressed in the inflorescence apex a few days after floral induction, and interacts with the floral-meri stemidentity gene floricaula to regulate flower position and morpholog y. The protein CEN is similar to animal proteins that associate with l ipids and GTP-binding proteins. We propose a model for how different i nflorescence structures may arise through the action and evolution of centroradialis.