Endofungal bacteria in Fusarium species producing mycotoxins in cereal

Fungi coexist with bacteria in the phytobiome through cellular interactions and collectively address various ecological functions. There are a small number of known associations in which certain bacteria reside inside the hyphae of fungi. These endohyphal bacteria seem to regulate key elements of the life cycle of fungi, induce the production of secondary metabolites useful in chemical dialogue with the plant and play a protective role for the host fungus under stress conditions. Recently, we have highlighted the frequent coexistence of bacterial strains belonging to the genus Stenotrophomonas with most of the studied strains of Fusarium tricinctum, one of the agents of Fusarium head blight producing mycotoxins.
association on the growth, reproduction and production of mycotoxins and other secondary metabolites by the fungus. These consequences will be observed (1) at the cellular level (followed by morphological modifications of the hyphae by differentiation of reserve spores (chlamydospores) capable of harboring the bacteria and ensuring the propagation of the two partners after fragmentation of the hypha), ( 2) at the physiological level (effect on fungal growth) and (3) at the molecular level, in particular by monitoring the production of secondary metabolites for antibacterial purposes such as bikaverine and the production of mycotoxins such as enniatins and beauvericin.
The second objective is to assess the occurrence of this type of association in a large panel of Fusarium spp. Fusarium head blight and mycotoxin producers
spp. with endohyphal bacteria and the study of their consequences on fitness factors of fungi will open the doors to the development of a new research axis for the understanding of the modulation of Fusarium pathogenicity and the search for  biocontrol agents.