Objective Symbiotic nitrogen fixation by rhizobia takes place in specialized organs of legume host plants, the root nodules. While rather deep molecular insights into plant-rhizobia recognition, early nodule organogenesis, regulation of nodulation and nitrogen fixation are available, much less is known about how nodule integrity is maintained and the origin of the underlying morphogenetic program. Recently, NOOT BOP COCH LIKE (NBCL) genes of Medicago truncatula and Pisum sativum were found to ensure nodule integrity by repressing ectopic root formation (applicant's former project). Interestingly, soybean nodules elicited by a Bradyrhizobium diazoefficiens mutant lacking the general stress response sigma factor σEcfG also formed ectopic roots (host's project), pointing to a bacteria-plant signalling system that is crucial for nodule persistence and integrity. Here, we propose to decipher the molecular determinants that maintain determinate nodule identity using the B. diazoefficiens – soybean model. We will combine plant molecular genetics, cell biology with transcriptomics and metabolomics to unravel cells, genes and metabolic networks that contribute to the checkpoint system ensuring nodule integrity. In work package 1 (WP1), the role of three soybean NBCL orthologs will be unravelled. In WP2, the nodule-to-root conversion characteristic for B. diazoefficiens ΔecfG mutants will be studied at the cellular level using root tip-specific reporter fusions. In WP3, a combination of metabolomics and transcriptomics will be applied to identify metabolites and gene networks involved in the nodule-to-root conversion elicited by ΔecfG and nbcl mutants. Altogether, results of this project will provide insight into determinants and mechanisms used by the economically important group of soybean plants to maintain the integrity of specialized, root-derived organs, an aspect that is relevant also in the light of ongoing attempts to engineer non-legumes into rhizobial hosts. Fields of science natural sciencesbiological sciencesmolecular biologymolecular geneticsnatural sciencesbiological sciencescell biologynatural sciencesbiological sciencesbiological behavioural sciencesethologybiological interactionsnatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymesagricultural sciencesagriculture, forestry, and fisheriesagriculturegrains and oilseedslegumes Keywords Glycine max (soybean) Bradyrhizobium diazoefficiens symbiosis NOOT EcfG sigma factor homeosis nodule organogenesis and development Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2016 - Individual Fellowships Call for proposal H2020-MSCA-IF-2016 See other projects for this call Funding Scheme MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF) Coordinator EIDGENOESSISCHE TECHNISCHE HOCHSCHULE ZUERICH Net EU contribution € 187 419,60 Address Raemistrasse 101 8092 Zuerich Switzerland See on map Region Schweiz/Suisse/Svizzera Zürich Zürich Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00
