VAJ/GFA1/CLO is involved in the directional control of floral organ growth

• Published in: Plant and cell physiology Vol. 50; no. 3; pp. 515 - 527
• Main Authors: Yagi, N.(Kyoto Univ. (Japan)), Takeda, S, Matsumoto, N, Okada, K
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01.03.2009; Oxford Publishing Limited (England)
• Subjects: Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; ARABIDOPSIS THALIANA; Cloning, Molecular; CRECIMIENTO; CROISSANCE; Directional organ growth; DNA, Bacterial - genetics; FLEUR; Floral organ development; FLORES; FLOWERS; Flowers - anatomy & histology; Flowers - genetics; Flowers - growth & development; GENE; Gene Expression Profiling; Gene Expression Regulation, Plant; GENES; Genetic Complementation Test; GROWTH; MORFOGENESIS; MORPHOGENESE; MORPHOGENESIS; Mutagenesis, Insertional; MUTANT; MUTANTES; MUTANTS; Mutation; Oligonucleotide Array Sequence Analysis; Peptide Elongation Factor 2 - genetics; Peptide Elongation Factor 2 - metabolism; Phenotype; Pre-mRNA splicing; RNA, Plant - genetics; Sequence Analysis, DNA; Directional organ growth; Floral organ development; Pre-mRNA splicing
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pcp011

Flowers assume variant forms of reproductive structures, a phenomenon which may be partially due to the diversity among species in the shape and size of floral organs. However, the organ size and shape of flowers usually remain constant within a species when grown under the same environmental conditions. The molecular and genetic mechanisms that control organ size and shape are largely unknown. We isolated an Arabidopsis mutant, vajra-1 (vaj-1), exhibiting defects in the regulation of floral organ size and shape. In vaj-1, alterations in the size and shape of floral organs were caused by changes in both cell size and cell number. The vaj-1 mutation also affected the number of floral organs. In vaj-1, a mutation was found in GAMETOPHYTIC FACTOR 1 (GFA1)/CLOTHO (CLO), recently shown to be required for female gametophyte development. The VAJ/GFA1/CLO gene encodes a translational elongation factor-2 (EF-2) family protein, of which the human U5-116kD and yeast Snu114p counterparts are U5 small nuclear ribonucleoprotein (snRNP)-specific proteins. A transient expression assay using Arabidopsis protoplasts revealed that VAJ protein co-localized with SC35, a serine/arginine-rich (SR) protein involved in pre-mRNA splicing. Our results showed that VAJ/GFA1/CLO has a novel role in the directional control of floral organ growth in Arabidopsis, possibly acting through pre-mRNA splicing.