CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Resources, Sichuan Agricultural University, 211 Huimin Road, Chengdu 611130, China.
CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Ecotoxicol Environ Saf. 2024 Jan 1;269:115739. doi: 10.1016/j.ecoenv.2023.115739. Epub 2023 Nov 27.
The root-associated microbiome assembly substantially promotes (hyper)accumulator plant growth and metal accumulation and is influenced by multiple factors, especially host species and environmental stress. Athyrium wardii (Hook.) is a phytostabilizer that grows in lead (Pb)-zinc (Zn) mine tailings and shows high root Pb accumulation. However, there remains little information on the assembly of the root-associated microbiome of A. wardii and its role in phytostabilization. A field study investigated the structural and functional variation in the root-associated bacterial microbiome of Athyrium wardii (Hook.) exposed to different levels of contamination in Pb-Zn mine tailings. The root compartment dominated the variation in the root-associated bacterial microbiome but the levels of contaminants showed less impact. Bacterial co-occurrence was enhanced in the rhizosphere soil and rhizoplane but tended to be much simpler in the endosphere in terms of network complexity and connectivity. This indicates that the microbial community assembly of A. wardii was non-random and shaped by root selective effects. Proteobacteria, Chloroflexi, Actinobacteria, Cyanobacteria, and Acidobacteriota were generally the dominant bacterial phyla. The genera Crossiella and Bradyrhizobium were enriched in the rhizosphere and cyanobacterial genera were enriched in the endosphere, demonstrating substantial advantages to plant survival and adaptation in the harsh mine environment. Functional categories involved in amino acid and carbohydrate metabolism were abundant in the rhizosphere soil, thus contributing to metal solubility and bioavailability in the rhizosphere. Membrane transporters, especially ATP-binding cassette transporters, were enriched in the endosphere, indicating a potential role in metal tolerance and transportation in A. wardii. The study shows substantial variation in the structure and function of microbiomes colonizing different compartments, with the rhizosphere and endophytic microbiota potentially involved in plant metal tolerance and accumulation during phytostabilization.
根相关微生物组的组装极大地促进了（超）积累植物的生长和金属积累，并受到多种因素的影响，特别是宿主物种和环境胁迫。蹄盖蕨（Hook.）是一种在铅锌矿尾矿中生长的植物稳定剂，具有较高的根铅积累能力。然而，关于蹄盖蕨根相关微生物组的组装及其在植物稳定化中的作用的信息仍然很少。一项野外研究调查了暴露于不同污染水平的铅锌矿尾矿中蹄盖蕨（Hook.）根相关细菌微生物组的结构和功能变化。根区是根相关细菌微生物组变异的主要控制因素，但污染物水平的影响较小。根际土壤和根面的细菌共现增强，但在根内区的网络复杂性和连通性方面则趋于更加简单。这表明，蹄盖蕨的微生物群落组装是非随机的，受根选择性效应的影响。变形菌门、绿弯菌门、放线菌门、蓝细菌门和酸杆菌门通常是主要的细菌门。交叉杆菌属和慢生根瘤菌属在根际中富集，蓝细菌属在根内区中富集，这表明它们在恶劣的矿山环境中对植物的生存和适应具有很大的优势。参与氨基酸和碳水化合物代谢的功能类群在根际土壤中丰富，因此有助于根际中金属的溶解度和生物利用度。膜转运蛋白，特别是 ATP 结合盒转运蛋白，在根内区中富集，表明它们在蹄盖蕨的金属耐受和运输中可能发挥作用。该研究表明，不同部位定殖的微生物组在结构和功能上存在很大的差异，根际和内生微生物群可能参与植物的金属耐受和积累过程，从而实现植物稳定化。
