The F-box-containing protein UFO and agamous participate in antagonistic pathways governing early petal development in Arabidopsis

Tim Durfee, Judith L. Roe, R. Allen Sessions, Carla Inouye, Kyle Serikawa, Kenneth A. Feldmann, Detlef Weigel, Patricia C. Zambryski

Research output: Contribution to journalArticle

56 Scopus citations


The UNUSUAL FLORAL ORGANS (UFO) gene is required for multiple processes in the developing Arabidopsis flower, including the proper patterning and identity of both petals and stamens. The gene encodes an F-box-containing protein, UFO, which interacts physically and genetically with the Skp1 homolog, ASK1. In this report, we describe four ufo alleles characterized by the absence of petals, which uncover another role for UFO in promoting second whorl development. This UFO-dependent pathway is required regardless of the second whorl organ to be formed, arguing that it affects a basic process acting in parallel with those establishing organ identity. However, the pathway is dispensable in the absence of AGAMOUS (AG), a known inhibitor of petal development. In situ hybridization results argue that AG is not transcribed in the petal region, suggesting that it acts non-cell-autonomously to inhibit second whorl development in ufo mutants. These results are combined into a genetic model explaining early second whorl initiation/proliferation, in which UFO functions to inhibit an AG-dependent activity.

Original languageEnglish (US)
Pages (from-to)8571-8576
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number14
StatePublished - Jul 8 2003


ASJC Scopus subject areas

  • General

Cite this