Florpyrauxifen-Benzyl Drives Dose- and Time-Dependent Changes in the Structure and Function of Fungal Communities in Rice Rhizosphere Soil by Modulating Soil Physicochemical Properties

Herbicides are critical for ensuring food production and improving agricultural yields; however, their residues may alter soil ecology and pose risks to animals, plants, and humans via bioaccumulation. Florpyrauxifen-benzyl is a novel herbicide, and existing studies have mainly focused on its weed control efficacy, crop safety, and general environmental impacts. However, the effects of its application on soil fungal diversity remain poorly understood. To elucidate the degradation pathways of florpyrauxifen-benzyl and its impacts on soil microorganisms, this study employed liquid chromatography and high-throughput sequencing to analyze florpyrauxifen-benzyl residues, shifts in soil physicochemical properties, and alterations in soil fungal communities following herbicide application, thereby revealing the interactions between florpyrauxifen-benzyl and soil fungi. Our results showed that, compared with the untreated control, the 10-fold recommended dose significantly increased the relative abundances of Pseudeurotium bakeri and Phialophora cyclaminis. Furthermore, the fungal diversity indices in the 5-fold and 10-fold recommended dose groups were significantly higher at later sampling stages than those in both the untreated control and the recommended-dose groups. After florpyrauxifen-benzyl application, the core fungal communities in the treatment groups were markedly distinct from those in the untreated control. These findings provide guidance for the safe and rational use of florpyrauxifen-benzyl, and offer a theoretical framework and scientific basis for the ecological monitoring of soil contamination and the elucidation of herbicide degradation mechanisms.