Abstract: Antibiotics and the resistance genes can enter farmland soil through fertilization of animal manure, bringing potential ecological risks to the soil-vegetable system. We examined the distribution characteristics of antibiotic resistance genes in the soil-vegetable system, with tetracycline resistance genes (TRGs) as a research object. The distribution characteristics of typical TRGs were analyzed in three kinds of raw vegetables (pakchoi, lettuce, cherry radish). The effects of vegetable root system disturbance on the diversity and abundance of TRGs in the rhizosphere soil were explored, and the correlation of TRGs between vegetable and soils were analyzed. The results showed that TRGs and mobile genetic elements (MGEs) were detected in vegetables and rhizosphere soil, with detection types and abundance following an order of rhizosphere soil>root>leaf. The types and abundances of TRGs and MGEs were higher in roots than in leaves of three tested vegetables. The detection rate and abundance of tetD-01, tetG-01, tet-T, tet(32), IS613, tnpA-04, intI-1(clinic) were prominent. TRGs and MGEs were higher in rhizosphere soil of cherry radish than that of lettuce and pakchoi. The distribution of some TRGs in soil and vegetable systems was significantly positively correlated with MGEs. Our results can provide data support for reveling the safety risks of TRGs in the soil-vegetable system.

Key words: agricultural soil, raw vegetable, tetracycline, antibiotic resistance gene, mobile genetic element