N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q), a transformation product of the widely used tire antioxidant 6PPD, has emerged as a ubiquitous environmental contaminant with potential risks to agroecosystems and food safety. This study systematically investigated the uptake, translocation, transformation, and transcriptomic responses of 6PPD-Q in the germinating leafy vegetable Ipomoea aquatica. In both the low and high exposure groups, 6PPD-Q preferentially accumulated in roots, reaching concentrations of 55.3±2.9 ng/g and1414.5±17.3 ng/g, respectively. High exposure to 6PPD-Q significantly inhibited seed germination and biomass accumulation, concomitant with the induction of oxidative stress. Nineteen 6PPD-Q transformation products were identified (e.g., C18H22N2O3, C22H27N5O9S, C24H34N2O7, C12H20N2O, and C7H13NO3), revealing novel metabolic pathways including glycosylation, methoxylation, glutathionylation, oxidization, and carboxylation. Notably, several transformation products (e.g., C19H24N2O2, C18H24N2O) were predicted to be more toxic than the parent compound, highlighting a potential secondary risk. Transcriptomic analysis suggested that the up-regulated genes encoding ABC transporters, cytochrome P450s, glutathione S-transferases, peroxidases, and UDP-glycosyltransferases likely played a role in the transmembrane transport and metabolic transformation of 6PPD-Q. Furthermore, the up-regulation of antioxidant genes coupled with the down-regulation of stress responsive genes indicated that 6PPD-Q exposure disrupted the balance between growth and stress response mechanisms. This study provides a comprehensive metabolic and molecular framework for understanding the fate of 6PPD-Q in a edible plant.