Effects of Microplastics on Endophytes in Different Niches of Chinese Flowering Cabbage (Brassica campestris)

Microplastics (MPs) are present in soil as emerging contaminants and pose a threat to soil as well as plants. Here, the effects of MPs on Chinese flowering cabbage from a microbiology perspective were explored. MP size and concentration significantly affected endophytic communities of plant root and petiole (p < 0.05). Under MP treatments, the root, petiole, and leaf exhibited a substantial abundance of pathogenic biomarkers, such as Pseudomonas, Burkholderia, Ralstonia, and Escherichia, resulting in the slow growth and morbidity of the plant. Difference analysis of metabolic pathways revealed that MPs significantly upregulated the pathogenic metabolic pathways (p < 0.05), and the presence of Vibrio infectious and pathogenic metabolic pathways was detected in all three niches of the plant. Moreover, MPs significantly inhibited the contents of carotenoids, iron, vitamin C, and calcium in edible niches of the plant (p < 0.05), and most of the high-abundant biomarkers were negatively correlated with their nutritional qualities.