College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, 225009, Jiangsu, China; College of Art Design, Yangzhou Polytechnic Institute, Yangzhou, 225107, Jiangsu, China.
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Environ Int. 2024 Aug;190:108904. doi: 10.1016/j.envint.2024.108904. Epub 2024 Jul 22.
Cadmium (Cd) contamination poses a significant threat to agricultural soils and food safety, necessitating effective remediation strategies. Salix species, with their high coverage and Cd accumulating capacity, hold promise for remediation efforts. The rhizosphere microbiome is crucial for enhancing Cd accumulating capacity for Salix. However, the mechanisms by how Salix interacts with its rhizosphere microbiome to enhance Cd extraction remains poorly understood. In this study, we compared the remediation performance of two Salix ecotypes: 51-3 (High Cd-accumulating Ecotype, HAE) and P646 (Low Cd-accumulating Ecotype, LAE). HAE exhibited notable advantages over LAE, with 10.80 % higher plant height, 43.80 % higher biomass, 20.26 % higher Cd accumulation in aboveground tissues (93.09 μg on average), and a superior Cd translocation factor (1.97 on average). Analysis of the rhizosphere bacterial community via 16S rRNA amplicon sequencing revealed that HAE harbored a more diverse bacterial community with a distinct composition compared to LAE. Indicator analysis identified 84 genera specifically enriched in HAE, predominantly belonging to Proteobacteria, Actinobacteria, and Firmicutes, including beneficial microbes such as Streptomyces, Bacillus, and Pseudomonas. Network analysis further elucidated three taxa groups specifically recruited by HAE, which were highly correlated with functional genes that associated with biosynthesis of secondary metabolites, glycan biosynthesis and metabolism, and metabolism of cofactors and vitamins. These functions contribute to enhancing plant growth, Cd uptake, and resistance to Cd in Salix. Overall, our findings highlight the importance of the rhizosphere microbiome in facilitating Cd extraction and provide insights into microbiome-based strategies for sustainable agricultural practices.
镉（Cd）污染对农业土壤和食品安全构成重大威胁，因此需要采取有效的修复策略。柳树属植物由于其高覆盖率和镉积累能力，在修复工作中具有很大的应用潜力。根际微生物组对于增强柳树的镉积累能力至关重要。然而，柳树与根际微生物组相互作用以增强镉提取的机制仍知之甚少。在本研究中，我们比较了两种柳树生态型的修复性能：51-3（高镉积累生态型，HAE）和 P646（低镉积累生态型，LAE）。HAE 表现出明显优于 LAE 的优势，其植物高度高出 10.80%，生物量高出 43.80%，地上组织中镉积累量高出 20.26%（平均为 93.09μg），且镉迁移因子更高（平均为 1.97）。通过 16S rRNA 扩增子测序对根际细菌群落进行分析，发现 HAE 拥有一个比 LAE 更加多样化的细菌群落，其组成也明显不同。指示分析确定了 84 个在 HAE 中特异性富集的属，主要属于变形菌门、放线菌门和厚壁菌门，包括有益微生物如链霉菌属、芽孢杆菌属和假单胞菌属。网络分析进一步阐明了 HAE 特异性招募的三个菌群组，这些菌群与与次生代谢物合成、聚糖生物合成和代谢以及辅助因子和维生素代谢相关的功能基因高度相关。这些功能有助于增强柳树的生长、镉吸收和对镉的抗性。总体而言，我们的研究结果强调了根际微生物组在促进镉提取中的重要性，并为基于微生物组的可持续农业实践策略提供了新的见解。
