Floral asymmetry involves an interplay between TCP and MYB transcription factors in Antirrhinum.
To understand how genes control floral asymmetry, we have isolated and analyzed the role of the RADIALIS (RAD) gene in Antirrhinum. We show that the RAD gene encodes a small MYB-like protein that is specifically expressed in the dorsal region of developing flowers. RAD has a single MYB-like domain that is closely related to one of the two MYB-like domains of DIV, a protein that has an antagonistic effect to RAD on floral development. Interactions between RAD and other genes indicate that floral asymmetry depends on the interplay between two pairs of transcription factors. First, a pair of TCP proteins is expressed in dorsal regions of the floral meristem, leading to the activation of RAD in the dorsal domain. The RAD MYB-like protein then antagonizes the related DIV MYB-like protein, preventing DIV activity in dorsal regions. In addition to its role in dorsal regions, RAD acts nonautonomously on lateral regions either directly, through RAD protein movement, or indirectly, through a signaling molecule.
Corley
Susie B
SB
Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich NR4 7UH, United Kingdom.
Carpenter
Rosemary
R
Copsey
Lucy
L
Coen
Enrico
E
D000595:Amino Acid Sequence; D032161:Antirrhinum / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D001483:Base Sequence; D005075:Biological Evolution; D019521:Body Patterning / Q000235:genetics; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017403:In Situ Hybridization; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D018744:DNA, Plant; D010940:Plant Proteins; D020598:Proto-Oncogene Proteins c-myb; D012333:RNA, Messenger; D018749:RNA, Plant; D014157:Transcription Factors