Molecular and genetic analyses of the silky1 gene reveal conservation in floral organ specification between eudicots and monocots

• Published in: Molecular cell 2000-03, Vol.5 (3), p.569-579
• Main Authors: Ambrose, B A, Lerner, D R, Ciceri, P, Padilla, C M, Yanofsky, M F, Schmidt, R J
• Format: Article
• Language: English
• Subjects: Adaptor Protein Complex alpha Subunits; Adaptor Proteins, Vesicular Transport; Biological Evolution; Cloning, Molecular - methods; DEFICIENS Protein; DNA Transposable Elements; DNA-Binding Proteins - genetics; Genes, Homeobox; Genes, Plant; Homeodomain Proteins - genetics; MADS Domain Proteins; Magnoliopsida - genetics; Membrane Proteins - genetics; Models, Biological; Morphogenesis - genetics; Mutation; Plant Proteins - genetics; Plant Shoots - anatomy & histology; Plant Shoots - genetics; Silky1 gene; Time Factors; Tissue Distribution; Transcription Factors - genetics; Zea mays; Zea mays - anatomy & histology; Zea mays - genetics
• ISSN: 1097-2765
• DOI: 10.1016/S1097-2765(00)80450-5

The degree to which the eudicot-based ABC model of flower organ identity applies to the other major subclass of angrosperms, the monocots, has yet to be fully explored. We cloned silky1 (si1), a male sterile mutant of Zea mays that has homeotic conversions of stamens into carpels and lodicules into palea/lemma-like structures. Our studies indicate that si1 is a monocot B function MADS box gene. Moreover, the si1 zag1 double mutant produces a striking spikelet phenotype where normal glumes enclose reiterated palea/lemma-like organs. These studies indicate that B function gene activity is conserved among monocots as well as eudicots. In addition, they provide compelling developmental evidence for recognizing lodicules as modified petals and, possibly, palea and lemma as modified sepals.