Alleviation of microplastic stress on Astragalus mongholicus by selenium-enriched microbial fertilizer

The impact of microplastic pollution on the ecological environment can no longer be ignored, especially the absorption process of microplastics by plants, which is becoming an important link in pollution transmission. At present, the governance of microplastic pollution has been gradually carried out. How to alleviate the impact of microplastics on the growth and development of plants will become the key breakthrough to prevent the spread of pollution and safeguard ecological security. In this study, the results of gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) indicated that microplastics could interfere with the glycolysis pathway, citrate cycle and flavonoid biosynthesisz of Astragalus mongholicus. The Enterobacter sp.H1 strain was screened out in the laboratory to develop microbial fertilizer. Through setting up microplastic stress and gradient selenium-enriched microbial fertilizer (HJ) intervention experiments, combined with multi-index determination and metabolomics analysis, investigate the molecular mechanism of selenium antagonizing microplastic stress. The results indicated that the application of HJ could alleviate Polystyrene microplastics (PS-MPs) stress in a dose-dependent manner. The repair was limited at low concentrations, high concentrations might cause excessive activation of metabolic pathways, and moderate concentrations had better comprehensive regulation. It could improve the stress-resistant phenotype, restore primary metabolic homeostasis, promote the accumulation of stress-resistant substances, enhance osmotic regulation, and form a synergistic defense system.