Role of EVERGREEN in the development of the cymose petunia inflorescence.
Plants species diverge with regard to the time and place where they make flowers. Flowers can develop from apical meristems, lateral meristems, or both, resulting in three major inflorescence types known as racemes, cymes, and panicles, respectively. The mechanisms that determine a racemose architecture have been uncovered in Arabidopsis and Antirrhinum. To understand how cymes are specified, we studied mutations that alter the petunia inflorescence. Here we show that EVERGREEN (EVG) encodes a WOX homeodomain protein, which is exclusively expressed in incipient lateral inflorescence meristems (IMs), promoting their separation from the apical floral meristem (FM). This is essential for activation of DOUBLE TOP and specification of floral identity. Mutations that change the cymose petunia inflorescence into a solitary flower fully suppress the evg phenotype. Our data suggest a key role for EVG in the diversification of inflorescence architectures and reveal an unanticipated link between the proliferation and identity of meristems.
Rebocho
Alexandra B
AB
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
Bliek
Mattijs
M
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
Kusters
Elske
E
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
Castel
Rob
R
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
Procissi
Antonia
A
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
Roobeek
Ilja
I
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
Souer
Erik
E
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
Koes
Ronald
R
Institute for Molecular and Cell Biology, Graduate School of Experimental Plant Sciences, Vrije Universiteit, de Boelelaan 1085, 1081HV Amsterdam, The Netherlands. Electronic address: ronald.koes@falw.vu.nl.
D000595:Amino Acid Sequence; D035263:Flowering Tops / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000033:anatomy & histology* / Q000502:physiology; D018398:Homeodomain Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D018519:Meristem / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D032306:Petunia / Q000033:anatomy & histology / Q000235:genetics; D010641:Phenotype; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
D018398:Homeodomain Proteins; D010940:Plant Proteins