Parental co-exposure to polystyrene nanoplastics and cadmium primes adaptive intergenerational responses in...

Micro/nanoplastics (MNPs), as emerging pollutants, have been detected globally in soil systems, where significant levels of heavy metals (HMs) also persist. The concomitant risks posed by these contaminants to agricultural production and food security have attracted considerable scientific attention. Nevertheless, critical gaps remain in understanding their long-term phytotoxicity, particularly concerning intergenerational effects. This study investigated the intergenerational impacts of polystyrene (PS) and cadmium (Cd) co-exposure on Arabidopsis thaliana. Our findings demonstrate that parental exposure to these stressors influences phenotypic traits in the offspring. The combined treatment of 100 mg/L PS and 5 mg/L Cd was particularly effective in triggering intergenerational responses. When offspring faced recurrent stress, parental exposure history conferred adaptive advantages. Specifically, offspring exhibited reduced Cd uptake in roots alongside enhanced Cd translocation and sequestration in shoots, a strategy likely mitigating free Cd ion toxicity. Transcriptomic analyses corroborated these phenotypic shifts, revealing that stressed offspring entered a generalized preventive state through altered resource allocation. Furthermore, distinct parental stress histories shaped unique adaptive strategies in the offspring. This study provides novel insights into the reproductive toxicity mechanisms of MNPs and HMs in plants, underscoring potential risks to generational plant health.