Department of Biology and Biotechnology of Microorganisms, The John Paul II Catholic University of Lublin, Lublin, Poland.
Department of Agricultural Microbiology, Institute of Soil Science and Plant Cultivation, State Research Institute, INCBR Centre, Puławy, Poland.
PLoS One. 2020 May 6;15(5):e0232699. doi: 10.1371/journal.pone.0232699. eCollection 2020.
The metal hyperaccumulator Azolla filiculoides is accompanied by a microbiome potentially supporting plant during exposition to heavy metals. We hypothesized that the microbiome exposition to selected heavy metals will reveal metal tolerant strains. We used Next Generation Sequencing technique to identify possible metal tolerant strains isolated from the metal-treated plant (Pb, Cd, Cr(VI), Ni, Au, Ag). The main dominants were Cyanobacteria and Proteobacteria constituting together more than 97% of all reads. Metal treatment led to changes in the composition of the microbiome and showed significantly higher richness in the Pb-, Cd- and Cr-treated plant in comparison with other (95-105 versus 36-44). In these treatments the share of subdominant Actinobacteria (0.4-0.8%), Firmicutes (0.5-0.9%) and Bacteroidetes (0.2-0.9%) were higher than in non-treated plant (respectively: 0.02, 0.2 and 0.001%) and Ni-, Au- and Ag-treatments (respectively: <0.4%, <0.2% and up to 0.2%). The exception was Au-treatment displaying the abundance 1.86% of Bacteroidetes. In addition, possible metal tolerant genera, namely: Acinetobacter, Asticcacaulis, Anabaena, Bacillus, Brevundimonas, Burkholderia, Dyella, Methyloversatilis, Rhizobium and Staphylococcus, which form the core microbiome, were recognized by combining their abundance in all samples with literature data. Additionally, the presence of known metal tolerant genera was confirmed: Mucilaginibacter, Pseudomonas, Mycobacterium, Corynebacterium, Stenotrophomonas, Clostridium, Micrococcus, Achromobacter, Geobacter, Flavobacterium, Arthrobacter and Delftia. We have evidenced that A. filiculoides possess a microbiome whose representatives belong to metal-resistant species which makes the fern the source of biotechnologically useful microorganisms for remediation processes.
金属超富集植物满江红共生微生物组在暴露于重金属时可能会支持植物。我们假设微生物组暴露于选定的重金属将揭示具有金属耐受性的菌株。我们使用下一代测序技术来鉴定从金属处理植物（Pb、Cd、Cr(VI)、Ni、Au、Ag）中分离出的可能具有金属耐受性的菌株。主要优势菌群是蓝藻和变形菌，它们共同构成了超过所有reads 的 97%。金属处理导致微生物组组成发生变化，与其他处理相比，Pb、Cd 和 Cr 处理植物的丰富度显著更高（95-105 对 36-44）。在这些处理中，亚优势菌群放线菌（0.4-0.8%）、厚壁菌门（0.5-0.9%）和拟杆菌门（0.2-0.9%）的比例高于未处理植物（分别为 0.02、0.2 和 0.001%）和 Ni、Au 和 Ag 处理（分别为 <0.4%、<0.2%和高达 0.2%）。例外是 Au 处理，其拟杆菌门的丰度为 1.86%。此外，通过将它们在所有样品中的丰度与文献数据相结合，识别出可能具有金属耐受性的属，即：不动杆菌属、Asticcacaulis、鱼腥藻属、芽孢杆菌属、短小芽孢杆菌属、伯克霍尔德氏菌属、Dyella、Methyloversatilis、根瘤菌属和葡萄球菌属，它们形成了核心微生物组。此外，还确认了已知具有金属耐受性的属的存在：粘细菌属、假单胞菌属、分枝杆菌属、棒状杆菌属、寡养单胞菌属、梭菌属、微球菌属、无色杆菌属、地杆菌属、黄杆菌属、节杆菌属和德氏菌属。我们已经证明，满江红拥有一个微生物组，其代表属于具有金属抗性的物种，这使得这种蕨类植物成为修复过程中生物技术有用微生物的来源。
