Two Lily SEPALLATA-like Genes Cause Different Effects on Floral Formation and Floral Transition in Arabidopsis

• Published in: Plant physiology (Bethesda) 2003-11, Vol.133 (3), p.1091-1101
• Main Authors: Tsai-Yu Tzeng, Chih-Chi Hsiao, Pei-Ju Chi, Yang, Chang-Hsien
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Amino Acid Sequence; Application programming interfaces; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biological and medical sciences; Classical and quantitative genetics. Population genetics. Molecular genetics; Development and Hormone Action; Economic plant physiology; Flowering; Flowering, floral biology, reproduction patterns; Flowers; Flowers - genetics; Flowers - growth & development; Flowers - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Generalities. Genetics. Plant material; Genes; Genes. Genome; Genetics and breeding of economic plants; Growth and development; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Inflorescences; Leaves; Lilium - genetics; Lilium - growth & development; Lilium - metabolism; Lilium longiflorum; MADS Domain Proteins - genetics; MADS Domain Proteins - metabolism; Models, Genetic; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Phenotypes; Phylogeny; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Plants, Genetically Modified; RNA; Sequence Homology, Amino Acid; Sexual reproduction; Transcription Factors - genetics; Transcription Factors - metabolism; Transgenic plants; Vegetative and sexual reproduction, floral biology, fructification
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.103.026997

Two AGL2-like MADS-box genes, Lily MADS Box Gene (LMADS) 3 and LMADS4, with extensive homology of LMADS3 to the Arabidopsis SEPALLATA3 were characterized from the lily (Lilium longiflorum). Both LMADS3 and LMADS4 mRNA were detected in the inflorescence meristem, in floral buds of different developmental stages, and in all four whorls of the flower organ. LMADS4 mRNA is also expressed in vegetative leaf and in the inflorescence stem where LMADS3 expression is absent. Transgenic Arabidopsis, which ectopically expresses LMADS3, showed novel phenotypes by significantly reducing plant size, flowering extremely early, and loss of floral determinacy. By contrast, 35S::LMADS4 transgenic plants were morphologically indistinguishable from wild-type plants. The early-flowering phenotype in 35S::LMADS3 transgenic Arabidopsis plants was correlated with the up-regulation of flowering time genes FT, SUPPRESSOR OF OVEREXPRESSION OF CO 1, LUMINIDEPENDENS, and flower meristem identity genes LEAFY and APETALA1. This result was further supported by the ability of 35S::LMADS3 to rescue the late-flowering phenotype in gigantea-1 (gi-1), constans-3 (co-3), and luminidependens-1 but not for ft-1 or fwa-1 mutants. The activation of these flowering time genes is, however, indirect because their expression was unaffected in plants transformed with LMADS3 fused with rat glucocorticoid receptor in the presence of both dexamethasone and cycloheximide.