Dissecting the process of plastid division in higher plants using functional genomics approaches

Plant cells contain plastids, vital organelles representing the ultimate source of all food production. Plastids are not created de novo but arise by division from pre-existing cytosolic plastids but despite recent progress in the field new approaches are needed to unravel this fundamental biological process. The objective of this proposal is to dissect plastid division in higher plants and to determine the integral nature of the process within plant cells by approaching it from a new angle using function al genomics approaches. Using yeast two-hybrid, immunoprecipitation, Bimolecular Fluorescence Complementation and Fluorescence Resonance Energy Transfer assays new plastid division proteins that interact with already characterized plastid division protein s will be identified. Interacting proteins will be analysed in terms of subcellular localisation and their role during division assessed by reverse genetics using loss-of-function and gain-of-function mutants. To determine the integral nature of the divis ion process within cells microarrays will be used to analyze nuclear gene expression dynamics in response to different plastid division states. To complement these studies quantitative chloroplast proteome analysis will be performed to determine chloropla st protein recruitment during division. Candidate proteins identified from both approaches will be analysed in terms of subcellular localisation and their role during division assessed by reverse genetics. In addition to the fundamental nature of this res earch the understanding of plastid division is vital for our continued research in designing new plastid genome engineering protocols for the use of plastids as biofactories for protein production. The research represents active collaborations between The University of Stavanger and five of the national FUGE platforms at The Universities of Oslo, Bergen, Trondheim and Life Sciences in addition to The University of Cambridge, UK and The Rockefeller University, USA