Nature 395, 561-566 (8 October 1998) | doi:10.1038/26903; Received 27 April 1998; Accepted 16 July 1998

A genetic framework for floral patterning

François Parcy1,2, Ove Nilsson1,2, Maximilian A. Busch1, Ilha Lee1,2 & Detlef Weigel1

  1. The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
  2. Present addresses: Institut des Sciences Végétales, CNRS, 91198 Gif-sur-Yvette Cedex, France (F.P.) Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden (O.N.) Department of Biology and Research Center for Cell Differentiation, Seoul National University, Seoul 151-742, Korea (I.L.).

Correspondence to: Detlef Weigel1 Correspondence and requests for materials should be addressed to D.W. (e-mail: Email:


The initial steps of flower development involve two classes of consecutively acting regulatory genes. Meristem-identity genes, which act early to control the initiation of flowers, are expressed throughout the incipient floral primordium. Homeotic genes, which act later to specify the identity of individual floral organs, are expressed in distinct domains within the flower. The link between the two classes of genes has remained unknown so far. Here we show that the meristem-identity gene LEAFY has a role in controlling homeotic genes that is separable from its role in specifying floral fate. On the basis of our observation that LEAFY activates different homeotic genes through distinct mechanisms, we propose a genetic framework for the control of floral patterning.