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

AIMS: Autotoxic phenolic compounds are released from decomposing plant litter and can accumulate in the soil. 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: The root litter decomposition experiment showed fungal communities in cucumber root litter differed between 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, p-coumaric, and p-hydroxybenzoic acids. A pot experiment demonstrated that Fusarium solani F60 decreased phenolic acid contents in soil and alleviated phenolic acid-induced toxicity to cucumber seedlings. CONCLUSIONS: This study shows that fungal community composition changes during root litter degradation, enriching Fusarium sp. capable of degrading phenolic acids.