Interactions between dark septate endophytes, ectomycorrhizal fungi and root pathogens in vitro

Charlotte Berthelot (1) , Corinne Leyval (1) , Michel Chalot (2) , Damien Blaudez (1)

1 LIEC - Laboratoire Interdisciplinaire des Environnements Continentaux
2 LCE - Laboratoire Chrono-environnement (UMR 6249)

Dark septate endophytes (DSEs) are widely distributed worldwide and can promote plant growth. Therefore, they are considered potentially important plant allies, especially in stressful environments. Previous studies reported that DSEs cohabit roots with other microorganisms such as ectomycorrhizal (ECM), endophytic and pathogenic fungi/ oomycetes. However, interactions between different DSE species have not yet been reported, and studies on the interactions between DSEs and other fungi are scarce. Using a simple and reproducible pairwise growth assay in vitro, we studied the synergistic/antagonistic interactions between eight DSEs, two ECM fungi and three root pathogens. Most of the DSE/DSE outcomes were neutral. Interestingly, we identified several DSE strains acting in synergy with other strains, as well as strains that could potentially act as biocontrol agents. Notably, three metal-tolerant DSE strains, namely, Cadophora sp., Leptodontidium sp. and Phialophora mustea, could decrease the growth of the root phytopathogens Pythium intermedium, Phytophthora citricola and Heterobasidion annosum. The present data are discussed in the general context of the use of fungal consortia as inocula in the tree-based phytomanagement of marginal lands.

Keywords: Dark septate endophyte; ectomycorrhizal fungi; root pathogenic fungi; Leptodontidium sp; Cadophora sp; Phialophora mustea; Phialocephala fortinii

Domains: Life Sciences [q-bio]

Charlotte Berthelot, Corinne Leyval, Michel Chalot, Damien Blaudez. Interactions between dark septate endophytes, ectomycorrhizal fungi and root pathogens in vitro. FEMS Microbiology Letters, 2019, 366 (13), ⟨10.1093/femsle/fnz158⟩. ⟨hal-02372472⟩