Physiological, cellular and growth effects of Eruca sativa exposed to microplastics and pesticides via elutriate and contaminated soil

• Grant number: 25/07791-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2025
• End date: September 30, 2026
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Amanda Pereira da Costa Araujo
• Grantee: Vanessa Silva Santos Matos
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 22/12104-4 - Fate and impacts of microplastics and pesticides in aquatic and terrestrial matrices in agricultural contexts, AP.TEM

Abstract

The simultaneous presence of microplastics (MPs) and pesticides in agricultural soils has raised significant concerns regarding their effects on terrestrial ecosystem functioning and plant development. Although soils receive MPs from diverse sources - including atmospheric deposition, sewage sludge application, mulching, and tire abrasion - most research to date has primarily focused on the impacts of these contaminants in marine and freshwater environments. Consequently, the effects of MPs, whether individually or in combination with pesticides, on the soil-plant system remain insufficiently understood. Recent studies have demonstrated that MPs can adsorb organic compounds such as pesticides, potentially increasing their environmental persistence and amplifying their toxic effects. Such interactions pose a threat to plant health and soil biodiversity.In this context, the present study aims to investigate the individual and combined effects of polyethylene (PE), the insecticide imidacloprid (IMD), and the fungicide tebuconazole (TBC) on the early development of Eruca sativa (rocket) through a series of phytotoxicity assays. Two experimental approaches will be employed: one involving direct exposure in contaminated soil and another utilizing soil elutriate to simulate the impacts of contaminant leaching. Potential adverse effects will be assessed based on parameters including germination rate, seedling growth and biomass, cell viability, and chlorophyll content in leaves - the latter serving as an indicator of photosynthetic potential. Pesticide quantification will be carried out using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), enabling the estimation of pesticide persistence and bioavailability in both soil and elutriate matrices.This research seeks to advance the understanding of the interactions between MPs and pesticides in tropical soils, thereby contributing to environmental risk assessment and supporting the development of more sustainable soil management practices in alignment with terrestrial ecosystem conservation. (AU)