Combined trace element pollution and drought severely limit plant performance and phytoremediation efficiency, highlighting the need for innovative mitigation strategies. This study evaluated whether foliar-applied fullerenol nanoparticles (FNP) enhance Alliaria petiolata resilience to metal pollution and combined metal-drought (WS) stress. The observed responses were dose-sensitive but strongly modulated by environmental context. FNP improved plant performances by increasing biomass, photosynthesis, and water status, with effects varying with concentration and soil condition. In polluted soil, biomass increased by 30% at 100FNP and 25% at 200FNP, whereas under combined stress the strongest stimulation (48%) occurred at 200WS. Drought-induced declines in relative water content were mitigated by FNP, with improvements of 15.7% (100WS) and 21.1% (200WS). Photosystem II efficiency also declined with drought, but was significantly stabilized by FNP. Antioxidant capacity was strongly enhanced under combined stress, APX, CAT, GPX, and PPO peaked at a lower FNP dose, while GSH increased 2.3-fold relative to the corresponding control. Simultaneously, oxidative damage markers (H₂O₂ and MDA) decreased in FNP-treated plants, indicating improved redox balance. Ionomic profiling revealed selective modulation of uptake and partitioning. FNP promoted foliar enrichment of Pb, Cd, and Zn under drought, while reducing Ni, Cr, and Cu allocation to leaves, and enhanced translocation of key nutrients (Zn, Mg, K) in a context-dependent manner. Multivariate analyses distinguished treatments by water status and FNP dose, revealing coordinated physiological and biochemical responses modulated by environmental context. These findings highlight FNP as a promising nanomaterial for buffering co-occurring stresses through coordinated regulation of redox balance, water status, and ion homeostasis. • Fullerenol (FNP) nanoparticles improve tolerance to metal and metal-drought co-stress • FNP enhances biomass, photosynthesis, and water status in a dose-specific manner. • FNP alters uptake and translocation of trace elements and nutrients • FNP upregulates antioxidant defense under combined stress conditions. • Dose-dependent responses of FNP suggest hormetic-like nanoparticle effects
Arsenov et al. (Fri,) studied this question.