The ABCs of flower development: mutational analysis of AP1/FUL-like genes in rice provides evidence for a homeotic (A)-function in grasses.
The well-known ABC model describes the combinatorial interaction of homeotic genes in specifying floral organ identities. While the B- and C-functions are highly conserved throughout flowering plants and even in gymnosperms, the A-function, which specifies the identity of perianth organs (sepals and petals in eudicots), remains controversial. One reason for this is that in most plants that have been investigated thus far, with Arabidopsis being a remarkable exception, one does not find recessive mutants in which the identity of both types of perianth organs is affected. Here we report a comprehensive mutational analysis of all four members of the AP1/FUL-like subfamily of MADS-box genes in rice (Oryza sativa). We demonstrate that OsMADS14 and OsMADS15, in addition to their function of specifying meristem identity, are also required to specify palea and lodicule identities. Because these two grass-specific organs are very likely homologous to sepals and petals of eudicots, respectively, we conclude that there is a floral homeotic (A)-function in rice as defined previously. Together with other recent findings, our data suggest that AP1/FUL-like genes were independently recruited to fulfil the (A)-function in grasses and some eudicots, even though other scenarios cannot be excluded and are discussed.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Feng
F
Wu
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of Chinese Academy of Sciences, Beijing, 100039, China.
Xiaowei
X
Shi
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Xuelei
X
Lin
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Yuan
Y
Liu
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Kang
K
Chong
Department of Genetics, Friedrich Schiller University Jena, D-07743, Jena, Germany.
Günter
G
Theißen
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Zheng
Z
Meng
D017360:Arabidopsis / Q000235:genetics; D035264:Flowers / Q000235:genetics / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D056626:Inflorescence / Q000235:genetics; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism; D018519:Meristem / Q000235:genetics / Q000254:growth & development; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000254:growth & development*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D006109:Poaceae / Q000235:genetics
D026161:MADS Domain Proteins; D010940:Plant Proteins
(A)-function; AP1-like genes; MADS-box gene; Oryza sativa ssp. L; homeotic gene