Objectif Plant cells have two kinds of cell elongation systems; diffuse growth and tip growth. Tip growth is highly polarized and the growth only occurs at the tip of the cell. Root hairs are tip growing projections that arise from specialised root epidermal cells. The localization of growth to the hair tip is controlled by the local production of reactive oxygen species (ROS) produced by the RHD2 NADPH oxidase. Therefore identifying and characterising proteins that spatially regulate RHD2 activity is central to understand the mechanism of tip growth. However, how and where RHD2 protein is activated and regulates the accumulation of ROS at the root hair tip is still unknown. Thus, the aims of this research are to determine the subcellular localization of RHD2 proteins and determine if RHD2 is directly regulated by small Rho GTPases called ROPs, which I predict regulate this NADPH oxidase. Firstly I will determine subcellular localization of RHD2 protein in root hair cells. I will use plants expressing an RHD2-YFP fusion protein in combination with confocal microscopy and spinning disc microscopy to investigate the protein localization during hair development. Secondly, I will identify and characterize the ROPs that are expressed during root hair development. After identification of root hair specific ROP by whole mount in situ hybridization, I will determine the subcellular localization of ROP using plants expressing ROP and CFP fusion protein. Thirdly, I will test if RHD2 physically interacts with ROP proteins. Because RHD2 is predicted to be a membrane protein, I will use split-ubiquitin yeast two-hybrid system to determine if RHD2 and ROP interact in vitro. For in vivo analysis, I will perform bimolecular fluorescence complementation (BiFC) and FRET approaches, both of which enable us to see the protein-protein interaction in developing root hairs. Together these analyses will define the mechanism of the RHD2 NADPH oxidase regulation during cell development. Champ scientifique natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsproteomicsnatural sciencesphysical sciencesopticsmicroscopyconfocal microscopy Mots‑clés RHD2 NADPH oxidase Rho-related GTPase from plants (ROP) root hair tip growth Programme(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Thème(s) MOBILITY-2.3 - Marie Curie Incoming International Fellowships (IIF) Appel à propositions FP6-2004-MOBILITY-7 Voir d’autres projets de cet appel Régime de financement IIF - Marie Curie actions-Incoming International Fellowships Coordinateur JOHN INNES CENTRE Contribution de l’UE Aucune donnée Adresse Norwich Research Park, Colney NORWICH Royaume-Uni Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée
