title: The differentiation of sepal and petal morphologies in Commelinaceae.
abstract: The morphological transition of the first whorl of tepals into sepals occurs frequently during the diversification of angiosperms. Such transitions may play important roles in pollination modes. The B class genes, APETALA3 (AP3) and PISTILLATA (PI) in Arabidopsis thaliana and GLOBOSA (GLO) and DEFICIENS (DEF) in Antirrhinum majus, are required for the development of petals in the second whorl, and its homologs have been isolated and characterized from various plants. A recent study on tulip, a monocotyledonous plant, indicates that the morphology of petaloid tepals in the first and second whorls is consistent with the expansion of B class gene expression. Here, we report five B class genes, TRGLOA, TRGLOB, CCGLO, TRDEF and CCDEF, isolated and characterized from two commelinaceous plants, Tradescantia reflexa and Commelina communis, with distinct sepal and petal morphologies in monocots. Northern blot analysis and gene-specific reverse transcription-polymerase chain reaction (RT-PCR) studies using dissected floral organs reveal a lack or low level of DEF-like gene expression in these commelinaceous species in the first whorl, in contrast to previous results. The expression data suggest that DEF-like gene expression in Commelinaceae correlates with the production of petaloid organs in the first whorl.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Ochiai
authors.forename: Toru
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Mashiko
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fukuda
authors.forename: Jun
authors.initials: J
authors.lastname: Yokoyama
authors.forename: Akira
authors.initials: A
authors.lastname: Kanno
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kameya
mesh_terms: D000595:Amino Acid Sequence; D015152:Blotting, Northern; D002454:Cell Differentiation; D034822:Commelina / Q000235:genetics* / Q000254:growth & development; D035264:Flowers / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D026161:MADS Domain Proteins / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D034823:Tradescantia / Q000235:genetics* / Q000254:growth & development
chemical_list: D026161:MADS Domain Proteins