本项目针对长残留除草剂土壤污染生物强化过程中引入的高效降解菌面临土著微生物竞争而难以存活的问题，以降解功能位于质粒pDOM的2甲4氯（MCPA）降解菌Cupriavidus gilardii为出发菌株，利用报道基因gfp标记降解质粒pDOM，研究质粒pDOM-gfp在土壤中的转移及其对 MCPA降解功能的持久性和纵深迁移性，明确质粒转移频率与受体菌种类、选择压、温湿度、养分、土壤类型的关系，探讨土壤中pDOM-gfp质粒转移的制约因子与驱动机制；并以pDOM-gfp质粒供体菌进行MCPA田间土壤污染生物强化研究，同期应用BIOLOG和PCR-TGGE评价强化过程中土壤微生物群落优势种群的结构和功能变化。研究结果可望阐明土壤微生物降解MCPA功能的形成机制，探索一条持续降解土壤长残留除草剂污染的新途径，对于控制或消减农田土壤中农药残留污染和保障土壤健康具有重要的科学意义和实际应用价值。

To overcome the poor survival and low activity of degrading-bacteria used for bioaugmentation of persistent herbicide in soil, this study focuses on transfer and vertical mobility of pDOM plasmid in soil and its effects on persistent degradation capacity of MCPA. The insertion of gfp segment into the pDOM plasmid in donor strain Cupriavidus gilardii is performed. The relationship between transfer frequency of pDOM-gfp plasmid and species of recipient strains, selective pressure of the herbicide, temperature, humidity, nutrient content, and soil types is evaluated in soil ecosystem. Restrictive factor and mechanism of pDOM-gfp plasmid transfer are conducted. A pDOM plasmid-mediated bioaugmentation is to be performed under field condition and soil microbial community structure and function is to be assessed by BIOLOG and PCR-TGGE techniques. The available results will be useful for delineating mechanism of degradation potential formation of MCPA by soil indigenous bacteria and for developing a plasmid-mediated bioaugmentation method that could result in the persistent capacity for the degradation of persistent herbicide in soil. These results would also provide a foundation for bioremediation of pesticide soil pollution and protecting soil health.