Plants Mitigate Nitrous Oxide Emissions from Antibiotic-Contaminated Agricultural Soils.

Vegetable production systems are hotspots of nitrous oxide (NO) emissions and antibiotic pollution. However, little is known about the interconnections among NO emissions, vegetable growth, and antibiotic contamination. To understand how plants regulate NO emissions from enrofloxacin (ENR)-contaminated soils, in situ NO emissions were measured in pot experiments with cherry radish and pakchoi. Gross NO production and consumption processes were discriminated based on an acetylene inhibition experiment. Results indicated that vegetable growth decreased the cumulative NO flux from 0.71 to -0.29 kg ha and mitigated the ENR-induced increase in NO emissions. Radish displayed better mitigation of NO emissions than pakchoi. By combining the analysis of NO flux with soil physicochemical and microbiological properties, we demonstrated that growing vegetables could either promote gross NO consumption or decrease gross NO production, primarily by interacting with soil nitrate, clade II ()-carrying bacteria, and . ENR inhibited NO consumption more than NO production, with the -carrying bacteria, represented by , as the main inhibition target. However, increasing -carrying bacteria by growing radish offsets the inhibitory effect of ENR. These findings provide new insights into NO emissions and antibiotic pollution in vegetable-soil ecosystems and broaden the options for mitigating NO emissions.