Insights on the translocation, metabolism, and subcellular distribution of mandipropamid enantiomers in spinach (Spinacia oleracea L.) and the effect of cultivation condition and heavy metal lead (Pb).

The fate of pesticides within crops is a critical determinant of environmental risk, influenced by various factors such as cultivation conditions and exogenous substances, which necessitate thorough investigation. This study examines the translocation, subcellular distribution, and metabolism of mandipropamid in spinach under different cultivation conditions and lead (Pb) stress. The pesticide is absorbed by roots (bioconcentration factors >1) and transported upward via symplast (high Kpw values in fresh roots), with limited downward translocation (translocation factors <1, αpt > 1). Cell walls are the primary accumulation site, and transport from soluble to solid fractions is evident (subcellular fraction concentration factors > > 1). Twelve metabolites were identified across three pathways. Spinach exhibits notable remediation efficiency in mandipropamid-contaminated soil/nutrient solutions, but Pb may prolong mandipropamid persistence, enhance tissue accumulation, and increase environmental risks. The findings provide insights into mandipropamid behavior and support bioremediation strategies for mandipropamid-contaminated environments.