Physiological and phytochemical responses of broccoli sprouts to micro/nanoplastics, elevated CO2 and heat stress under a predictive modeling framework

Broccoli sprouts ( Brassica oleracea L. var. italica ) are valuable sources of bioactive phytochemicals with nutritional and functional relevance. Their metabolic responses are highly sensitive to environmental factors, yet the combined effects of climate-related and contaminant stressors remain poorly understood. This study evaluated the interactive influence of elevated CO 2 (1000 ppm), temperature (28 °C), and micro/nanoplastics (MNPs) on the physiological and phytochemical responses of broccoli sprouts. Temperature was the main driver, enhancing total glucosinolates (10–71%) but decreasing biomass (1–13%), revealing a clear growth–defense trade-off. CO 2 enrichment exerted moderate, context-dependent effects, stimulating glucosinolates and anthocyanins synthesis at 20 °C but attenuating them under heat. MNPs acted as secondary modulators, slightly influencing phytohormone and phenolic profiles through indirect interactions. Multivariate and neural-network modeling (R 2 = 0.86–0.94) confirmed temperature as the dominant factor leading metabolic reprogramming toward sulfur- and phenylpropanoid-based defenses. These results demonstrate that predictive modeling can effectively integrate multistress physiological responses, offering new insights into plant adaptability and the functional quality of edible sprouts under future climate and contaminant scenarios.