Updated project metadata. Two diazotrophic bacteria, BPMP-PU-28 and BPMP-EL-40, isolated from the rhizosphere of a wild wheat ancestor (T. t. dicoccoides) grown in soil from its refuge area in the Fertile Crescent or from south of France, respectively, were shown to behave as efficient Plant Growth Promoting Rhizobacteria (PGPR) upon interaction with an elite wheat cultivar (Anvergur), providing about 50% of the seed nitrogen content in plants grown under low assimilable nitrogen availability. A bacterial growth medium was developed to investigate the effects of bacterial exudates on root development in the elite cultivar and to analyze the exo-metabolomes and exo-proteomes of the two strains. Altered root development was observed, with distinctive responses according to the strain, BPMP-PU-28 also inducing a strong increase in root hair length and density. Exo-metabolome analysis revealed a complex set of secondary metabolites including fatty acids potentially involved in volatile organic compounds (VOCs) metabolism, cyclopeptides that could act as phytohomone mimetics, quorum sensing molecules having inter-kingdom signaling properties and nutrient ion chelators. The exo-proteome comprised a set of strain specific enzymatic activities (e.g., proteases) and structural proteins belonging to outer-membrane vesicles likely to sequester metabolites, peptides and enzymes in their lumen. Thus, the wheat ability to establish efficient beneficial interactions with PGPR has not been profoundly reprogrammed during domestication and breeding, and PGPR constitutively exude rich and complex metabolomes and proteomes, in absence of partner roots, which could allow numerous mechanisms to simultaneously contribute to plant growth promotion and thereby broaden the range of responsive plant species.