UFO: an Arabidopsis gene involved in both floral meristem and floral organ development.

We describe the role of the UNUSUAL FLORAL ORGANS (UFO) gene in Arabidopsis floral development based on a genetic and molecular characterization of the phenotypes of nine ufo alleles. UFO is required for the proper identity of the floral meristem and acts in three different aspects of the process that distinguishes flowers from shoots. UFO is involved in establishing the whorled pattern of floral organs, controlling the determinacy of the floral meristem, and activating the APETALA3 and PISTILLATA genes required for petal and stamen identity. In many respects, UFO acts in a manner similar to LEAFY, but the ufo mutant phenotype also suggests an additional role for UFO in defining boundaries within the floral primordia or controlling cell proliferation during floral organ growth. Finally, genetic interactions that prevent flower formation and lead to the generation of filamentous structures implicate UFO as a member of a new, large, and diverse class of genes in Arabidopsis necessary for flower formation.

[1]  E. Meyerowitz,et al.  Function and regulation of the Arabidopsis floral homeotic gene PISTILLATA. , 1994, Genes & development.

[2]  S. Shannon,et al.  Genetic Interactions That Regulate Inflorescence Development in Arabidopsis. , 1993, The Plant cell.

[3]  E. Lord,et al.  Floral development in Arabidopsis thaliana: a comparison of the wild type and the homeotic pistillata mutant , 1989 .

[4]  A. Arber.  STUDIES IN FLORAL MORPHOLOGY1. II. ON SOME NORMAL AND ABNORMAL CRUCIFERS: WITH A DISCUSSION ON TERATOLOGY AND ATAVISM , 1931 .

[5]  I. Sussex,et al.  LEAFY Interacts with Floral Homeotic Genes to Regulate Arabidopsis Floral Development. , 1992, The Plant cell.

[6]  M. Van Montagu,et al.  Control of Arabidopsis flower and seed development by the homeotic gene APETALA2. , 1994, The Plant cell.

[7]  Elliot M. Meyerowitz,et al.  The ABCs of floral homeotic genes , 1994, Cell.

[8]  I. Sussex,et al.  Function of the apetala-1 gene during Arabidopsis floral development. , 1990, The Plant cell.

[9]  Cindy Gustafson-Brown,et al.  Molecular characterization of the Arabidopsis floral homeotic gene APETALA1 , 1992, Nature.

[10]  K. Okada,et al.  Isolation and characterization of novel mutants of Arabidopsis thaliana defective in flower development , 1988 .

[11]  E. Meyerowitz,et al.  CLAVATA 3 is a specific regulator of shoot and floral meristem development affecting the same processes as CLAVATA 1 , 1995 .

[12]  E. Meyerowitz,et al.  CLAVATA1, a regulator of meristem and flower development in Arabidopsis. , 1993, Development.

[13]  G. Haughn,et al.  AP2 Gene Determines the Identity of Perianth Organs in Flowers of Arabidopsis thaliana. , 1989, The Plant cell.

[14]  D Weigel,et al.  Activation of Floral Homeotic Genes in Arabidopsis , 1993, Science.

[15]  Elliot M. Meyerowitz,et al.  Control of flower development in Arabidopsis thaliana by APETALA1 and interacting genes , 1993 .

[16]  Hong Ma,et al.  The protein encoded by the Arabidopsis homeotic gene agamous resembles transcription factors , 1990, Nature.

[17]  J. Bowman,et al.  Negative regulation of the Arabidopsis homeotic gene AGAMOUS by the APETALA2 product , 1991, Cell.

[18]  J. Matthews.  A Manual of Aquatic Plants , 1940, Nature.

[19]  W. Nacken,et al.  Genetic Control of Flower Development by Homeotic Genes in Antirrhinum majus , 1990, Science.

[20]  Elliot M. Meyerowitz,et al.  The homeotic gene APETALA3 of Arabidopsis thaliana encodes a MADS box and is expressed in petals and stamens , 1992, Cell.

[21]  J. Alvarez,et al.  terminal flower: a gene affecting inflorescence development in Arabidopsis thaliana , 1992 .

[22]  D. Weigel,et al.  SUPERMAN, a regulator of floral homeotic genes in Arabidopsis. , 1992, Development.

[23]  E. Meyerowitz,et al.  Arabidopsis homeotic gene APETALA3 ectopic expression: Transcriptional and posttranscriptional regulation determine floral organ identity , 1994, Cell.

[24]  J L Bowman,et al.  Genes directing flower development in Arabidopsis. , 1989, The Plant cell.

[25]  E M Meyerowitz,et al.  LEUNIG regulates AGAMOUS expression in Arabidopsis flowers. , 1995, Development.

[26]  E. Coen,et al.  The war of the whorls: genetic interactions controlling flower development , 1991, Nature.

[27]  D. Weigel,et al.  LEAFY controls floral meristem identity in Arabidopsis , 1992, Cell.

[28]  R. Simon,et al.  Fimbriata controls flower development by mediating between meristem and organ identity genes , 1994, Cell.