Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Ministry of Education, College of Environmental Science and Engineering, Nankai University , Tianjin , China.
College of Geography and Tourism, Chongqing Normal University , Chongqing , China.
Int J Phytoremediation. 2019;21(12):1161-1169. doi: 10.1080/15226514.2019.1612841. Epub 2019 May 17.
Rhizodegradation performed by plant roots and the associated bacteria is one of the major mechanisms that contribute to removal of petroleum hydrocarbons (PHCs) during phytoremediation. In this study, the pot-culture experiment using wild ornamental (Boreau) H. Ohba was designed to explore responses and roles of roots, microbes, and degrading genes in the rhizodegradation process. Results showed that PHCs degradation rate by phytoremediation was up to 37.6-53.3% while phytoaccumulation accounted for a low proportion, just at 0.3-13.3%. A total of 37 phyla were classified through the high throughput sequencing, among which , , and were the three most dominant phyla, accounting for >60% of the phylum frequency. The selective enrichment of PHC degraders with high salt-tolerance, including and , was induced. Generally, relative abundance of the PHC degrading genes increased significantly with an increase in PHCs concentrations, and the gene copy number in the phytoremediation group was 1.46-14.44 times as much as that in the unplanted controls. Overall, the presence of PHCs and plant roots showed a stimulating effect on the development of specific degraders containing PHC degrading genes, and correspondingly, a biodegradation-beneficial community structure had been constructed to contribute to PHCs degradation in the rhizosphere.
植物根系及其相关细菌的根际降解作用是植物修复去除石油烃（PHC）的主要机制之一。本研究采用盆栽实验，利用野生观赏植物（Boreau）H. Ohba 探索了根际降解过程中根、微生物和降解基因的响应和作用。结果表明，植物修复对 PHC 的降解率高达 37.6-53.3%，而植物吸收仅占很小的比例，仅为 0.3-13.3%。通过高通量测序共分类出 37 个门，其中 、 和 是最主要的三个门，占门频率的>60%。选择性富集了具有高耐盐性的 PHC 降解菌，包括 和 。一般来说，随着 PHCs 浓度的增加，PHC 降解基因的相对丰度显著增加，修复组的基因拷贝数是未种植对照组的 1.46-14.44 倍。总之，PHC 的存在和植物根系对含有 PHC 降解基因的特定降解菌的发展表现出刺激作用，相应地，构建了有利于 PHC 降解的生物降解有益群落结构。
