Persistent versus transient, and conventional plastic versus biodegradable plastic? —Two key questions about microplastic-water exchange of antibiotic resistance genes

•ARG exchange between MPs and receiving waters is universal and active but transient.•ARG exchange between MPs and water facilitates horizontal gene transfer.•ARGs tend to converge between MPs and receiving water with evolution time.•Biodegradable PBAT generally enriches higher ARG abundance than PET.•Multidrug resistance genes tend to accumulate on biodegradable PBAT.