The environmental pollutants of arsenic and microplastics mediating soil microbiota shift aphid growth in tobacco

Environmental pollutants are ubiquitous and persistent in soil, water, and air, posing serious threats to biodiversity, ecological functions, and human health. The application of agricultural chemicals has led to the release of large amounts of environmental pollutants, which have driven a rapid shift in ecological function via mediating community composition in agroecosystems. In this study, we employed 16S rRNA amplicon sequencing, coupled with phenotypic determination of tobacco (Nicotiana tabacum) and aphid (Myzus persicae), to explore the multi-trophic responses of a soil microbiome-tobacco-aphid system to arsenic (As) and microplastics (MPs) stress. Soil residues of As and MPs significantly reduced the species diversity of soil microorganisms and led to shift of microbial community function. Notably, the relative abundances of specific taxa, such as Gemmatimonas and Edaphobaculum, increased following As and MPs exposure, whereas Aquicella and Phycicoccus exhibited a significant decline in contrast. Furthermore, MPs increased the size of tobacco leaves and stem circumference. However, the growth rate of tabaco height significantly decreased with MPs residues in the soil. The As exposure reduced the size and number of effective tobacco leaves. The behavioural experiment revealed that aphid was attracted by As-stressed tobacco leaves more than control. Interestingly, M. persicae exhibited enhanced growth and reproduction on As-stressed leaves, while showing a partially adverse response to MPs exposure. Therefore, As exposure increased the growth rate and catastrophic collapse of aphid populations. Consequently, environmental pollutants affect the complex ecological network among microorganisms, plants, and insects, and pose potential threats to the structural stability and functional integrity of agricultural ecosystems.