"Plant growth is remarkably flexible in response to changing environmental conditions, which is especially important as human life depends on the production of plant materials and they are now also being explored as a source of non-fossil fuels. The proposed project aims to reveal novel regulatory mechanisms that control developmental processes in response to environmental stresses. Mitogen-activated protein (MAP) kinase pathways have been in the focus of stress signalling research in plants for over a decade. On the other hand our recent results strongly suggest a role for a MAP kinase pathway in the regulation of meristem activity. We propose that the underlying mechanism is the regulation of transcription factors that are key regulators of stem cell identity and meristem development by direct MAP kinase phosphorylation. This notion is supported by our bioinformatics prediction of potential MAP kinase substrates as well as by proteomics data. Our goal is to generate biochemical and functional genetics evidence for the cross-talk between known MAP kinase and meristem regulatory pathways in the model plant Arabidopsis. To this end we will commence with testing the phosphorylation status of candidate MAP kinase substrates using efficient novel approaches. In the second part of the project a couple of the most intriguing substrates and their relation to MAP kinase pathways will be genetically analysed. Thus the proposed experimental program can provide important novel biological information of major agricultural significance."