Final Report Summary - SIREN (Signals and regulatory networks in early plant embryogenesis) Signals and regulatory networks in early plant embryogenesis (SIREN) Understanding mechanisms of early embryogenesis is central to reveal the logic of developmental processes that build the plant. Early embryogenesis, starting from a single cell, lays down the foundation of plant development including the initiation of the primary stem-cell systems of shoot and root that subsequently generate all structures of the adult plant. Before the start of this project, individual research groups had addressed different aspects of early embryogenesis. The information about the underlying mechanisms was, however, rather fragmented and therefore progress was limited. Moreover, mono-disciplinary approaches such as genomics, proteomics or genetics all have inherent limitations, which called for a strategy that integrates these different disciplines. A second sticking point was the technical limitations inherent to the location of plant embryos within seeds and fruits. These limitations were to be overcome by sharing expert knowledge and a sophisticated technology platform. The identification of a number of key regulators of early embryogenesis finally created the unique situation where early plant embryogenesis could be deeply and systematically investigated. This was the right time to build the SIREN network in order to decipher the logic of signals and regulatory networks that orchestrate early embryogenesis and to bring together the fragmented knowledge about the underlying mechanisms. Additionally, it was the right moment to train the next generation of plant developmental biologists on this new and wide range of modern technologies and comprehensive background knowledge. In particular, the project aimed to generate understanding of signals and regulatory networks in early plant embryogenesis by using a unique combination of complementary experimental approaches. In the initial phase, new technologies and methodologies were established or adapted to the specific conditions of early embryogenesis. These tools were then used to identify cell type-specific gene expression profiles and to dissect their transcriptional regulation. Target genes of key cell-fate regulators were defined and finally, integration of signalling mechanisms was addressed. The project has significantly improved our understanding of early embryogenesis and this is equally important for the plant biology community as well as the agro-industry and thus, the European research area. Many genes expressed in specific cell types were identified. Inventories of regulatory connections involving key cell-fate regulators were established. Nevertheless, modelling of regulatory network is still limited by the complexity of the system. In addition to the improved knowledge, expressed in a number of publications in high-profile journals, the industrial partner Intavis AG has developed novel applications and instrument adaptations for automated high-throughput in-situ hybridisation (HT-ISH) of plant embryos. In essence, the same applications or adaptations will allow HT-ISH for other small samples, such as cultured cells or tissues of animals. Training of early-stage researchers (ESRs) played an important part of SIREN's activities. In addition to mentoring of individual ESRs in their host laboratory, technical workshops and specific seminars on soft skills were organised. ESRs also actively participated in the annual meetings of the SIREN partners, giving progress reports, and they successfully presented their projects at a meeting on plant embryogenesis with international experts as invited speakers. Website: http://siren.punkt-international.eu/ Contact: Gerd Juergens, Center for Plant Molecular Biology (ZMBP), University of Tübingen, Germany, gerd.juergens@zmbp.uni-tuebingen.de
