title: Detection of recombinant Pseudomonas putida in the wheat rhizosphere by fluorescence in situ hybridization targeting mRNA and rRNA.
abstract: A method was developed to detect a specific strain of bacteria in wheat root rhizoplane using fluorescence in situ hybridization and confocal microscopy. Probes targeting both 23S rRNA and messenger RNA were used simultaneously to achieve detection of recombinant Pseudomonas putida (TOM20) expressing toluene o-monooxygenase (tom) genes and synthetic phytochelatin (EC20). The probe specific to P. putida 23S rRNA sequences was labeled with Cy3 fluor, and the probe specific to the tom genes was labeled with Alexa647 fluor. Probe specificity was first determined, and hybridization temperature was optimized using three rhizosphere bacteria pure cultures as controls, along with the P. putida TOM20 strain. The probes were highly specific to the respective targets, with minimal non-specific binding. The recombinant strain was inoculated into wheat seedling rhizosphere. Colonization of P. putida TOM20 was confirmed by extraction of root biofilm and growth of colonies on selective agar medium. Confocal microscopy of hybridized root biofilm detected P. putida TOM20 cells emitting both Cy3 and Alexa647 fluorescence signals.
authors.affiliation: Environmental Toxicology Graduate Program, University of California, Riverside, CA, 92521, USA.
authors.forename: Cindy H
authors.initials: CH
authors.lastname: Wu
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Hwang
authors.forename: Wonkyu
authors.initials: W
authors.lastname: Lee
authors.forename: Ashok
authors.initials: A
authors.lastname: Mulchandani
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Wood
authors.forename: Marylynn V
authors.initials: MV
authors.lastname: Yates
authors.forename: Wilfred
authors.initials: W
authors.lastname: Chen
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D016956:Burkholderia cepacia / Q000201:enzymology; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D054811:Phytochelatins / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology*; D016958:Pseudomonas putida / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D012329:RNA, Bacterial / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D012680:Sensitivity and Specificity; D014908:Triticum / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012338:RNA, Ribosomal, 23S; D054811:Phytochelatins; D006899:Mixed Function Oxygenases