Li Mingyue, Xu Minmin, Su Aoxue, Zhang Ying, Niu Lili, Xu Yan
College of Environmental Sciences and Engineering, Qingdao University, Qingdao, China.
Shandong Academy of Environmental Sciences Co., Ltd., Jinan, China.
Front Microbiol. 2022 May 4;13:888086. doi: 10.3389/fmicb.2022.888086. eCollection 2022.
Combined organic and inorganic pollutants can greatly impact crops and microbes, but the interaction between coexisted pollutants and their effects on root-associated microbes under flooding conditions remains poorly understood. In this study, greenhouse experiments were conducted to investigate the individual and combined effects of phenanthrene (PHE) and copper (Cu) on rice uptake and root-associated microbial coping strategies. The results showed that more than 90% of phenanthrene was degraded, while the existence of Cu significantly reduced the dissipation of PHE in the rhizosphere, and the coexistence of phenanthrene and copper promoted their respective accumulation in plant roots. Copper played a dominant role in the interaction between these two chemicals. Microbes that can tolerate heavy metals and degrade PAHs, e.g., , Sphingobacteriales, and Saccharimonadales, were enriched in the contaminated soils. Additionally, microbes associated with redox processes reacted differently under polluted treatments. Fe reducers increased in Cu-treated soils, while sulfate reducers and methanogens were considerably inhibited under polluted treatments. In total, our results uncover the combined effect of heavy metals and polycyclic aromatic hydrocarbons on the assemblage of root-associated microbial communities in anaerobic environments and provide useful information for the selection of effective root-associated microbiomes to improve the resistance of common crops in contaminated sites.
有机和无机污染物的组合会对作物和微生物产生重大影响，但在淹水条件下共存污染物之间的相互作用及其对根际微生物的影响仍知之甚少。在本研究中，进行了温室试验，以研究菲（PHE）和铜（Cu）对水稻吸收及根际微生物应对策略的单独和联合影响。结果表明，超过90%的菲被降解，而铜的存在显著降低了根际中菲的消散，且菲和铜的共存促进了它们在植物根系中的各自积累。铜在这两种化学物质的相互作用中起主导作用。能够耐受重金属并降解多环芳烃的微生物，如鞘脂杆菌目和糖单胞菌目，在污染土壤中富集。此外，与氧化还原过程相关的微生物在污染处理下反应不同。铁还原菌在铜处理的土壤中增加，而硫酸盐还原菌和产甲烷菌在污染处理下受到显著抑制。总的来说，我们的结果揭示了重金属和多环芳烃对厌氧环境中根际微生物群落组合的联合影响，并为选择有效的根际微生物群落以提高常见作物在污染场地的抗性提供了有用信息。
