PubMed · 2026-04-17
The rust-colored iron coating that forms naturally on wetland plant roots acts as a double-edged filter for antibiotic resistance: it amplifies the spread of resistance genes among bacteria on the root surface while simultaneously blocking those genes from entering the plant itself, pointing toward new strategies for using wetland plants to clean contaminated water.
Iron plaque on root surfaces increased antibiotic resistance gene transfer frequency in a dose-dependent manner — the more iron plaque that formed, the more gene swapping occurred on the root surface.
Iron plaque significantly reduced antibiotic resistance gene transfer into the root interior, acting as a physical and chemical barrier that declined transfer as plaque thickness grew.
Gammaproteobacteria such as Escherichia and Pseudomonas drove over 70% of all resistance gene transfer events despite comprising less than 3% of the total bacterial community.