Effects of dark septate endophytic fungi on the performance of nonmycorrhizal cabbage plants under normal and low water conditions

Alena F LukácsGábor HerczegGábor M. Kovács^*

• Institute of Biology, Faculty of Science, Eötvös Loránd University, Budapest, Hungary

Drought, a major issue linked to global environmental change, significantly threatens both natural and agricultural ecosystems. Root-associated fungi, particularly the widely distributed dark septate endophytes (DSE) are key members of the plant microbiome and can influence host plant performance in various ways. We conducted two manipulative experiments using two model DSE species originating from a semi-arid habitat to investigate their effects on a non-mycorrhizal host plant (cabbage) under both normal and reduced water supply conditions. The positive effects of Periconia were limited, increasing root biomass at the cost of lowering water potential and soil humidity under normal water regime. Cadophora significantly increased shoot biomass (with up to 50 %) and in one experiment the root biomass, though this was again associated with a decline of plant water potential, particularly in the low water regime. Both isolates improved plants growth performance at a cost in plant water status, but their effects differed on the same host. Interestingly, the autoclaved inoculum with no living fungi also had positive effects on plants growth. Our findings highlight the potential role of symbiotic DSE fungi in mitigating drought stress and suggest their promise as biotechnological tools for addressing the growing challenge of drought.