Bisphenol A contamination in irrigation water compromises tomato (Solanum lycopersicum) performance and food safety through oxidative and molecular stress pathway

Bisphenol A (BPA) is a pervasive endocrine-disrupting compound increasingly detected in wastewater effluents and reclaimed irrigation water, raising concerns for crop health and food safety. This study investigated the physiological, biochemical, and molecular responses of tomato ( Solanum lycopersicum L. cv. Roma VF [NH5]) exposed to BPA-contaminated irrigation water under controlled greenhouse conditions at the Institute of Agricultural Research and Training, Obafemi Awolowo University, and the National Horticultural Research Institute, Ibadan, Nigeria. Plants were irrigated with 0, 50, 100, and 200 µg L⁻¹ BPA for 30 days, and growth, photosynthetic traits, oxidative stress biomarkers, antioxidant defense, and stress-related gene expression were assessed. BPA exposure significantly reduced plant height, chlorophyll content (SPAD), and photosystem II efficiency (Fv/Fm), with declines most pronounced at 200 µg L⁻¹. Lipid peroxidation increased by 171% relative to control,which indicated severe oxidative damage. Antioxidant enzymes (superoxide dismutase, catalase, peroxidase) and their corresponding genes (SlSOD, SlCAT, SlPOD) were markedly upregulated, reflecting activation of the redox defense system. Moreover, a 2.7-fold induction of SlHSP70 expression suggested generalized molecular stress responses and proteostasis disruption.Hence, these findings demonstrated that even environmentally relevant BPA levels can impair tomato plant growth and photosynthetic performance via oxidative and molecular stress pathways. Beyond productivity losses, the results showed that potential risks for food quality and human exposure under wastewater reuse practices. Monitoring and mitigation strategies are urgently needed to minimize BPA contamination in agricultural irrigation systems and safeguard both crop performance and food safety.