Fusarium solani isolated from decomposing cucumber root litter degrades autotoxic phenolics and promotes cucumber growth

Aims: During plant litter decomposition, phenolic compounds are released and accumulate in the soil, inducing plant autotoxicity. This study investigates the dynamics of the fungal community during root litter decomposition and the potential of fungal communities in root litter for degrading phenolic compounds.Methods and Results: In this study, a root litter decomposition experiment showed fungal communities in cucumber root litter exhibited significant differences on 15 and 60 days after decomposition. In particular, Fusarium sp. was enriched in root litter. Then, we isolated a strain of interest, coded F60, from the root litter and identified it as Fusarium solani. This strain achieved in vitro degradation rates exceeding 90% for ferulic acid, p-coumaric acid, and p-hydroxybenzoic acid. A pot experiment demonstrated that the F60 inoculation decreased phenolic acids in soil and alleviated phenolic acid-induced toxicity to cucumber seedlings.Conclusions: Overall, this study shows that fungal community composition alters during root litter degradation, enriching Fusarium sp. capable of degrading phenolic acids.Impact Statement: Our results indicate that F60 has significant potential in alleviating soil sickness, and this provides a potential microbial resource for the biological removal of phenolic acids.