title: A tripartite microbial reporter gene system for real-time assays of soil nutrient status.
abstract: Plant-derived carbon is the substrate which drives the rate of microbial assimilation and turnover of nutrients, in particular N and P, within the rhizosphere. To develop a better understanding of rhizosphere dynamics, a tripartite reporter gene system has been developed. We used three lux-marked Pseudomonas fluorescens strains to report on soil (1) assimilable carbon, (2) N-status, and (3) P-status. In vivo studies using soil water, spiked with C, N and P to simulate rhizosphere conditions, showed that the tripartite reporter system can provide real-time assessment of carbon and nutrient status. Good quantitative agreement for bioluminescence output between reference material and soil water samples was found for the C and P reporters. With regard to soil nitrate, the minimum bioavailable concentration was found to be greater than that analytically detectable in soil water. This is the first time that bioavailable soil C, N and P have been quantified using a tripartite reporter gene system.
authors.affiliation: Department of Plant and Soil Science, School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen AB24 3UU, Scotland, UK. d.standing@abdn.ac.uk
authors.forename: Dominic
authors.initials: D
authors.lastname: Standing
authors.forename: Andy A
authors.initials: AA
authors.lastname: Meharg
authors.forename: Ken
authors.initials: K
authors.lastname: Killham
mesh_terms: D000217:Acyltransferases; D001426:Bacterial Proteins; D002244:Carbon / Q000378:metabolism*; D003199:Computer Systems; D017930:Genes, Reporter; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D008163:Luminescent Measurements; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D009584:Nitrogen / Q000378:metabolism*; D010088:Oxidoreductases; D010710:Phosphates / Q000378:metabolism / Q000494:pharmacology; D010758:Phosphorus / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000032:analysis; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D014733:Vibrio / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D009566:Nitrates; D010710:Phosphates; D011993:Recombinant Fusion Proteins; D012987:Soil; D010758:Phosphorus; D002244:Carbon; D010088:Oxidoreductases; C055198:LuxC protein, Bacteria; D000217:Acyltransferases; C034919:acyl protein synthetase; C065928:luxD protein, Bacteria; D005947:Glucose; D009584:Nitrogen; C018279:sodium phosphate; C006568:ammonium nitrate