植物根系对粪肥施用土壤中抗生素抗性基因的选择性消除及机理研究

随着抗生素的大量使用，抗生素抗性基因 (Antibiotic resistance genes, ARGs) 在环境中的丰度和多样性不断增长，给人类健康带来隐患。常年施用禽畜粪便等农家肥的土壤是ARGs污染的重灾区。植物的生长对土壤ARGs有较大影响，申请人发现土壤中部分ARGs的丰度在植物种植后显著降低，且随植物种植代数的增加而降低至检测阈值下，其背后的机制仍然未知。本项目以多年施用粪肥的土壤为基质，在其中多代种植大豆或水稻，使用高通量PCR检测每代植物种植前后土壤中ARGs的变化(包括根际土和非根际土)，结合多种组学技术研究根系分泌物对土壤ARGs的影响规律和相关机理，找出关键的根系分泌物组分并进行验证。最终，阐明植物对土壤ARGs的选择性修复机制。该项目研究为植物修复ARGs污染，特别是在长期施用粪肥的土壤这一实际环境的ARGs修复提供理论支持。

With the increasing use of antibiotics, the abundance and diversity of antibiotic resistance genes (ARGs) show a growing trend in the environment, which is a hidden danger to human health. Soil applied with livestock manure is one of the most serious ARGs pollution areas. Plant growth has a great influence on soil ARGs. We found that the abundance of some ARGs in soil was significantly reduced after planting, and even below detectable limit after continuous cropping. The mechanism behind this phenomenon is still unknown. In this project, soybean and rice continuous cropping will be carried out in the soil treated with manure. Variations of ARGs in soil, including rhizosphere soil and non-rhizosphere soil, before and after planting of each batch of plants will be detected by high-throughput PCR. The effects of root exudates on soil ARGs and related mechanisms will be studied by using a variety of omics techniques. Key components of root exudates will be identified and verified. Finally, the mechanism of plant selective remediation of ARGs in soil will be elucidated. An accurate understanding of the selection rules and mechanisms of soil ARGs by plants, especially in the practical environment of long-term application of manure, can provide a theoretical support for repairing ARGs pollution by using plants.