Impact of interbacterial competition through type VI secretion systems (T6SS) on the dynamics of the seed microbiota

As a result, the diversity of the seed microbiota tends to be limited, with few dominant taxons when compared with other habitats in the plant. However, considerable diversity is maintained in the microbial assemblies of seeds. The composition and functions of these assemblies can partly be explained by their diversified metabolic capacities. The compositions of microbiotas can also be regulated by interbacterial interactions by means of specific antimicrobial weapons. Some dominant bacterial phyla in seeds are endowed with such weapons, such as type VI secretion systems (orT6SS) that target other micro-organisms with antimicrobial effectors. At present, the contributions of such secretion systems to the assembly of the seed microbiota, and implicitly to seed performance, are not known. This project aims to explore the role of bacterial T6SS in the dynamics of microbiota assembly in brassica seeds and their direct or indirect impact on the transmission of pathogenic agents by seeds.