RESUMO
In vascular plants, the regulation of stem cell niche determines development of aerial shoot which consists of stems and lateral organs. Intercalary meristem (IM) controls internode elongation in rice and other grasses, however little attention has been paid to the underlying mechanism of stem cell maintenance. Here, we investigated the stem development in rice and showed that the Shortened Uppermost Internode 1 (SUI1) family of genes are pivotal for development of rice stems. We demonstrated that SUI-family genes regulate the development of IM for internode elongation and also the cell expansion of the panicle stem rachis in rice. The SUI-family genes encoded base-exchange types of phosphatidylserine synthases (PSSs), which possessed enzymatic activity in a yeast complementary assay. Overexpression of SUI1 and SUI2 caused outgrowths of internodes during vegetative development, and we showed that expression patterns of Oryza Sativa Homeobox 15 (OSH15) and Histone4 were impaired. Furthermore, genome-wide gene expression analysis revealed that overexpression and RNA knockdown of SUI-family genes affected downstream gene expression related to phospholipid metabolic pathways. Moreover, using Ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry, we analyzed PS contents in different genetic backgrounds of rice and showed that the quantity of very long chain fatty acids PS is affected by transgene of SUI-family genes. Our study reveals a new mechanism conveyed by the SUI1 pathway and provides evidence to link lipid metabolism with plant stem cell maintenance.
Assuntos
CDPdiacilglicerol-Serina O-Fosfatidiltransferase/genética , Oryza/genética , Proteínas de Plantas/genética , Caules de Planta/genética , Sequência de Aminoácidos , CDPdiacilglicerol-Serina O-Fosfatidiltransferase/classificação , CDPdiacilglicerol-Serina O-Fosfatidiltransferase/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Giberelinas/farmacologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hibridização In Situ , Isoenzimas/genética , Isoenzimas/metabolismo , Microscopia Confocal , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Mutação , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Fosfatidilserinas/metabolismo , Filogenia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/ultraestrutura , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/genética , Homologia de Sequência de AminoácidosRESUMO
Investigation of gene function in diverse organisms relies on knowledge of how the gene products interact with each other in their normal cellular environment. The Bimolecular Fluorescence Complementation (BiFC) Assay(1) allows researchers to visualize protein-protein interactions in living cells and has become an essential research tool. This assay is based on the facilitated association of two fragments of a fluorescent protein (GFP) that are each fused to a potential interacting protein partner. The interaction of the two protein partners would facilitate the association of the N-terminal and C-terminal fragment of GFP, leading to fluorescence. For plant researchers, onion epidermal cells are an ideal experimental system for conducting the BiFC assay because of the ease in obtaining and preparing onion tissues and the direct visualization of fluorescence with minimal background fluorescence. The Helios Gene Gun (BioRad) is commonly used for bombarding plasmid DNA into onion cells. We demonstrate the use of Helios Gene Gun to introduce plasmid constructs for two interacting Arabidopsis thaliana transcription factors, SEUSS (SEU) and LEUNIG HOMOLOG (LUH)(2) and the visualization of their interactions mediated by BiFC in onion epidermal cells.