Transcriptome and metabolome analyses uncover nanoplastic induced oxidative stress responses in peach roots

Nanoplastics (NPs) are tiny particles generated through plastic degradation. Currently, research on NPs in plants mainly focuses on algae and food crops, while studies on fruit trees are limited. In this study, we examined the influence of different concentrations (0, 2, 4, 8, 16, and 32 mg/L) of PS-NPs (Polystyrene Nanoplastics) on the growth and development of the 'Qingzhou' peach (Prunus persica (L.) Batsch) and Prunus davidiana Franch root systems. PS-NPs were taken up by peach roots, and 32 mg/L PS-NP treatment induced oxidative stress in the roots across both varieties and caused H₂O₂ and O₂^- accumulation in vivo, inhibiting root elongation. To resolve the regulatory network induced by NPs, integrated transcriptome and metabolome sequencing analysis of peach root systems administered 0 and 32 mg/L PS-NPs suggested that 32 mg/L PS-NPs treatment produced a PpCRTISO-mediated oxidative cascade response by up-regulating the transcription of PpNRT2.7. In this process, PS-NPs down-regulated Dopamine levels in 'Qingzhou' peach and L-Cysteine in Prunus davidiana Franch, disrupting non-enzymatic antioxidant systems and causing an imbalance of ROS homeostasis. Further, the equilibrium between oxidation and antioxidants was disrupted, inducing oxidative stress responses in the root system. These findings are critical for deciphering the interactions and defense mechanisms between NPs and fruit trees, as well as reducing the negative impacts of NPs on fruit trees.