Chemical ecology in phytoremediation: Mechanistic insights, knowledge gaps, and future research directions

Phytoremediation harnesses plants efficiently to mitigate environmental pollutants, providing an eco-friendly alternative to conventional remediation technologies. Despite of decades physiological and molecular research, phytoremediation performance often remains context-dependent and challenging to predict, partly due to an incomplete understanding of chemically mediated interactions among plants, microbes, and contaminants in complex soil and water environments. This review synthesizes insights from chemical ecology to evaluate how root exudates, volatile organic compounds (VOCs), and allelochemicals orchestrate rhizosphere dynamics, microbial community assembly, and contaminant speciation and transformation. We focus on key knowledge gaps, including limited mechanistic validation of metabolite-microbe-pollutant interactions, insufficient integration of multi-omics datasets with ecological and physicochemical variables, and methodological challenges in field translation. While recent multi-omics approaches have expanded molecular resolution, their integration with ecological context and spatiotemporal dynamics remains limited. By highlighting emerging approaches and interdisciplinary strategies, this review outlines key research directions toward mechanistic, predictive, and ecologically grounded phytoremediation frameworks. It is a roadmap for advancing predictive, ecologically informed phytoremediation systems.