MADS-box protein complexes control carpel and ovule development in Arabidopsis.
The AGAMOUS (AG) gene is necessary for stamen and carpel development and is part of a monophyletic clade of MADS-box genes that also includes SHATTERPROOF1 (SHP1), SHP2, and SEEDSTICK (STK). Here, we show that ectopic expression of either the STK or SHP gene is sufficient to induce the transformation of sepals into carpeloid organs bearing ovules. Moreover, the fact that these organ transformations occur when the STK gene is expressed ectopically in ag mutants shows that STK can promote carpel development in the absence of AG activity. We also show that STK, AG, SHP1, and SHP2 can form multimeric complexes and that these interactions require the SEPALLATA (SEP) MADS-box proteins. We provide genetic evidence for this role of the SEP proteins by showing that a reduction in SEP activity leads to the loss of normal ovule development, similar to what occurs in stk shp1 shp2 triple mutants. Together, these results indicate that the SEP proteins, which are known to form multimeric complexes in the control of flower organ identity, also form complexes to control normal ovule development.
Favaro
Rebecca
R
Dipartimento di Biologia, Università di Milano, 20133 Milano, Italy.
Pinyopich
Anusak
A
Battaglia
Raffaella
R
Kooiker
Maarten
M
Borghi
Lorenzo
L
Ditta
Gary
G
Yanofsky
Martin F
MF
Kater
Martin M
MM
Colombo
Lucia
L
D026342:AGAMOUS Protein, Arabidopsis / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D030821:Plants, Genetically Modified; D012639:Seeds / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D026342:AGAMOUS Protein, Arabidopsis; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D026161:MADS Domain Proteins; C476012:SEEDSTICK protein, Arabidopsis; C121158:SEP3 protein, Arabidopsis; C419044:SHP1 protein, Arabidopsis; C419045:SHP2 protein, Arabidopsis; D014157:Transcription Factors