title: Molecular characterization and functional analysis of a Flowering locus T homolog gene from a Phalaenopsis orchid.
abstract: Warm day and cool night conditions significantly induce reproductive spike formation in Phalaenopsis plants; hence, determining the flowering mechanism regulating the reproductive transition is important. Flowering locus T (FT) plays important roles in flowering induction in several plants. To explore spike induction by warm days and cool nights in Phalaenopsis orchids, we isolated the FT (PhFT) from Phalaenopsis hybrid Fortune Saltzman. The cDNA of PhFT was 809-bp long and contained a 531-bp open reading frame encoding a putative protein of 176 amino acids, a 58-bp 5'-untranslated region (UTR), and a 220-bp 3'-UTR. The predicted molecular mass of PhFT was 19.80 kDa, with an isoelectric point of 8.68. The PhFT was predicted to possess the conserved functional regions of the phosphatidylethanolamine-binding protein superfamily. Nucleotide sequence data indicated that PhFT contained 3 introns and 4 exons. Sequence alignment and phylogenetic analyses of PhFT revealed high homology to the FT proteins of Cymbidium goeringii and Oncidium Gower Ramsey. Quantitative real-time polymerase chain reaction analysis indicated that PhFT mRNA was expressed in roots, apical leaves, mature leaves, and flowers. In flowers, PhFT was expressed more in developing floral buds than in mature flowers and was predominantly expressed in ovaries and petals. Ectopic expression of PhFT in Arabidopsis ft-1 mutants showed novel early-flowering phenotypes that lost their siliques. Our results indicated that the ectopic expression of PhFT could partially complement the late flowering defect in transgenic Arabidopsis ft-1 mutants. Our findings suggest that PhFT is a putative FT homolog in Phalaenopsis plants that regulates flowering transition.
authors.affiliation: Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China biology.li2008@163.com.
authors.forename: D M
authors.initials: DM
authors.lastname: Li
authors.affiliation: Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
authors.forename: F B
authors.initials: FB
authors.lastname: L
authors.affiliation: Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
authors.forename: G F
authors.initials: GF
authors.lastname: Zhu
authors.affiliation: Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
authors.forename: Y B
authors.initials: YB
authors.lastname: Sun
authors.affiliation: Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
authors.forename: H L
authors.initials: HL
authors.lastname: Liu
authors.affiliation: Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
authors.forename: J W
authors.initials: JW
authors.lastname: Liu
authors.affiliation: Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D023061:Gene Order; D017343:Genes, Plant; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D029595:Orchidaceae / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D010802:Phylogeny; D040641:Quantitative Trait Loci; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary