Resolving colocalization of bacteria and metal(loid)s on plant root surfaces by combining fluorescence in situ hybridization (FISH) with multiple-energy micro-focused X-ray fluorescence (ME μXRF)
| Autor: | Raina M. Maier, Linnea K. Honeker, Robert A. Root, Jon Chorover |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Microbiology (medical) DNA Bacterial media_common.quotation_subject 010501 environmental sciences 01 natural sciences Microbiology Plant Roots Article Actinobacteria Metal 03 medical and health sciences RNA Ribosomal 16S Gammaproteobacteria Soil Pollutants Molecular Biology In Situ Hybridization Fluorescence Phylogeny Soil Microbiology 0105 earth and related environmental sciences media_common biology Bacteria X-Rays Alphaproteobacteria Colocalization Plants biology.organism_classification Phytoremediation Speciation 030104 developmental biology Genes Bacterial Metals visual_art Environmental chemistry visual_art.visual_art_medium Synchrotrons Electron Probe Microanalysis Environmental Monitoring |
| Zdroj: | Journal of microbiological methods. 131 |
| ISSN: | 1872-8359 |
| Popis: | Metal(loid)-contamination of the environment due to anthropogenic activities is a global problem. Understanding the fate of contaminants requires elucidation of biotic and abiotic factors that influence metal(loid) speciation from molecular to field scales. Improved methods are needed to assess micro-scale processes, such as those occurring at biogeochemical interfaces between plant tissues, microbial cells, and metal(loid)s. Here we present an advanced method that combines fluorescence in situ hybridization (FISH) with synchrotron-based multiple-energy micro-focused x-ray fluorescence microprobe imaging (ME μXRF) to examine colocalization of bacteria and metal(loid)s on root surfaces of plants used to phytostabilize metalliferous mine tailings. Bacteria were visualized on a small root section using SytoBC nucleic acid stain and FISH probes targeting the domain Bacteria and a specific group (Alphaproteobacteria, Gammaproteobacteria, or Actinobacteria). The same root region was then analyzed for elemental distribution and metal(loid) speciation of As and Fe using ME μXRF. The FISH and ME μXRF images were aligned using ImageJ software to correlate microbiological and geochemical results. Results from quantitative analysis of colocalization show a significantly higher fraction of As colocalized with Fe-oxide plaques on the root surfaces (fraction of overlap 0.49 ± 0.19) than to bacteria (0.072 ± 0.052) (p < 0.05). Of the bacteria that colocalized with metal(loid)s, Actinobacteria, known for their metal tolerance, had a higher correlation with both As and Fe than Alphaproteobacteria or Gammaproteobacteria. This method demonstrates how coupling these micro-techniques can expand our understanding of micro-scale interactions between roots, metal(loid)s and microbes, information that should lead to improved mechanistic models of metal(loid) speciation and fate. |
| Databáze: | OpenAIRE |
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