Development of a TaqMan® probe-based real-time PCR approach to track the biological control agent Pseudomonas poae RE*1-1-14

Abstract: The sugar beet endophyte Pseudomonas poae RE*1-1-14 is a component of anantagonistic cocktail developed to control root rot diseases in sugar beet. Based on an extendedscreening process the microbial compilation also includes the rhizobacteria P. fluorescensL13-6-12 and Serratia plymuthica 3Re4-18. To assess cell numbers during the seed treatmentprocedure, subsequent storage of the inoculated seeds and, finally, in course of plantdevelopment, a quantitative real-time PCR method was established for the model strain P. poaeRE*1-1-14. For cultivation-independent monitoring of the population dynamics of the strain, wedeveloped a pair of SCAR (Sequence Characterized Amplified Regions) primer for a specific580 bp fragment derived from a comparative U-PCR approach. In combination with a strainspecificprobe, the primer set was suitable to be employed in a TaqMan® real-time PCR assay.The described system allows the accurate detection and quantification of the antagonist in sugarbeet seed coatings and ad planta under greenhouse conditions.