Studying plant responses to micro- and nanoplastics: a review of experimental design and analytical methods

With increasing concern regarding microplastic and nanoplastic pollution, growing attention has been directed toward their potential impacts on ecosystems and plant health. However, while most existing reviews focus on toxicological effects, structured discussions regarding experimental design remain limited in areas such as substrate selection and environmental parameter control. This review evaluates current progress by identifying prevalent polymer types like polystyrene (PS) and polyethylene (PE), common particle sizes (notably 10 m to 100 m), and representative exposure concentrations (100 mg L^-1 to 1000 mg L^-1). It also assesses practical procedures for substrate preparation and sterilization, alongside cultivation parameters including temperature (25 ^ to 27 ^), relative humidity (40% to 70%), and photoperiod regimes. Furthermore, this review evaluates common plant response indicators, spanning physiological and biochemical traits such as chlorophyll content, biomass, and antioxidant enzyme activity to molecular-level assessments including transcriptomics and metabolomics. By synthesizing these procedural elements, this review proposes a standardized framework to enhance reproducibility and technical consistency. This structured approach facilitates better alignment across different studies and serves as a practical guide for future plant–microplastic research.