An interdisciplinary approach is employed to elucidate plant centrosome formation, functioning and regulation with respect to cell proliferation to develop new concepts for the optimization of growth and biomass accumulation in plants. Recently, biochemical and molecular work in Drosophila melanogaster has resulted in the identification of a large number of novel genes encoding components of the centrosome that play a central role in cell proliferation. Although higher plants lack a classical centrosome/centriole structure, there is evidence that protein function at the molecular level is conserved. Here, we will transfer the knowledge derived from the analysis of Drosophila centrosomes to the higher plants Arabidopsis thaliana (and partly to Oryza sativa) by identifying and characterising corresponding genes and their products. The main objectives of the proposed project are the following: (a) to identify genes encoding higher plant centrosomal proteins and to analyse their expression patterns during cell cycle progression / cell proliferation and as a response to the application of growth-affecting stimuli (metabolites, nutrients, hormones, abiotic stress); (b) to study the cellular role of these genes with respect to the regulation of growth processes in plants; and (c) to identify novel (also plant-specific) proteins of centrosomal complexes using a biochemical approach. The advancement of knowledge resulting from these objectives is not only central to cell biology but will also have a great potential for agricultural / industrial applications.