Assessing the ecological impact and microbial restoration of quinclorac-contaminated paddy fields through high-throughput sequencing technology

Quinclorac (QNC) is a highly selective herbicide with hormone-like properties and low toxicity, primarily employed to control barnyard grass in paddy fields. Owing to its extended half-life, it readily accumulates in soil, thereby inhibiting the growth and development of subsequent crops. Additionally, long-term residual accumulation of QNC has notable repercussions on soil microbial communities. Certain bacteria capable of degrading QNC have been identified, effectively diminishing its soil residues and thus mitigating its ecological impact. For the first time, high-throughput sequencing technology (Illumina MiSeq) was employed to assess the influence of both QNC and the newly isolated QNC-degrading bacterial strain D on soil microorganisms in contaminated paddy fields. The study yielded significant findings: substantial variances were observed in the composition and structural diversity of microbial communities across various treatments. Furthermore, strain D demonstrated a restorative effect on microbial community composition and structural diversity. QNC was found to suppress specific functions within soil bacteria and fungi, altering the constitution of functional groups. Interestingly, strain D counteracted the suppressive effect of QNC, contributing positively to the restoration of soil microbial ecology. Consequently, this research offers a novel strain resource and a theoretical foundation for microbiologically mitigating QNC contamination in paddy fields.