Micro- and nano-plastics in the environment have been widely concerned due to their large specific surface area, low surface polarity, and easy adsorption and accumulation of other pollutants. Combined stress of nanoplastics (NPs) and arsenic (As) greatly threatens aquatic plants, but the underlying molecular mechanisms of combined exposure remain unclear.

Researchers from the Aquatic Plants and Aquatic Ecosystem Health Group of Wuhan Botanical Garden conducted comprehensive multi-omics analysis of aquatic plant (Vallisneria denseserrulata) under single or combined NPs and As exposure.

This study revealed varying degrees of inhibition on the physiological traits of V. denseserrulata under different stress conditions, demonstrating that NPs-As co-stress showed the most pronounced physiological inhibition compared to either stress alone, with As exerting dominant effects.

The integrated transcriptomic and metabolomic analysis revealed three key defensive response mechanisms of V. denseserrulata in response to NPs and As co-stress. Firstly, carbon fixation and photosynthesis antenna protein pathways regulated photosynthetic intensity in response to NPs-As co-contamination. Secondly, energy conversion through upregulated biosynthetic pathways reduced the damage of V. denseserrulata. Finally, the stimulation of phenylpropane metabolism and fatty acid metabolism impacted lipid peroxidation and antioxidant activity, thus elevating growth and mitigating toxicity.

The findings have important implications for assessing the ecological risks of emerging contaminants and protecting vulnerable aquatic ecosystems. Further cross-species validation can confirm the generalizability of these key pathways and biomarkers of stress resistance.

The research titled “Drilling into the physiology, transcriptomics, and metabolomics to enhance insight on Vallisneria denseserrulata responses to nanoplastics and metalloid co-stress” was published in the Journal of Cleaner Production.

This study was supported by the National Natural Science Foundation of China, Sino-Africa Joint Research Center, Chinese Academy of Sciences, Hubei Provincial Natural Science Foundation of China and Knowledge Innovation Program of Wuhan-Shuguang Project.