The F-box-containing protein UFO and AGAMOUS participate in antagonistic pathways governing early petal development in Arabidopsis.
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.
Durfee
Tim
T
Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
Roe
Judith L
JL
Sessions
R Allen
RA
Inouye
Carla
C
Serikawa
Kyle
K
Feldmann
Kenneth A
KA
Weigel
Detlef
D
Zambryski
Patricia C
PC
D026342:AGAMOUS Protein, Arabidopsis / Q000502:physiology*; D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D035264:Flowers / Q000254:growth & development*; D009024:Morphogenesis / Q000235:genetics; D025941:Protein Interaction Mapping; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017384:Sequence Deletion; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
D026342:AGAMOUS Protein, Arabidopsis; C120363:ASK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C098247:UFO protein, Arabidopsis