Potential impact of polyethylene on the growth of pakchoi(Brassica campestris L.):Endophyte effects
In the current study,pakchoi(Brassica campestris L.)was selected and pot experiments were conducted to investigate the potential impact of polyethylene microplastic(PE-MPs)addition at different size and levels on the growth and physiological and biochemical variations of pakchoi.PE exposure resulted in a significant decrease in height and weight of pakchoi(P<0.05),with decreased by 86.8%and 60.3%,respectively,at PE particle size of 0.5 μm,addition level of 0.5%(w/w).Meanwhile,PE exposure resulted in a significant decrease in photosynethics pigments concentrations in leaves of pakchoi(P<0.05).Two-way ANOVA results indicated that the PE particle size has greater impact on the growth of pakchoi and the variations of photosynethics pigments concentrations.In addtions,PE exposure resulted in a significant decrease in both Shannon and ACE indices for bacteria(P<0.05),and a significant increased of Simpson index for fungi(P<0.05).Moreover,the relative abundance of Proteobacteria and Ascomycota increased,while the relative abundance of Actinobacteriota decreased under different PE additions.SEM images showed that PE-MPs occurred mostly in the xylem and cell walls of the root cortical tissues of pakchoi.Two-way ANOVA results indicated that the PE particle size has greater impact on oxidative stress contents.PE exposure causing serious structural and functional damage and membrane lipid peroxidation damage of pakchoi,and leading to a decrease in pakchoi biomass.
Brassica campestris L.polyethylene microplasticsendophytereactive oxygen species