Session: 813 Antibacterial targets and drug discovery II
(813.1) Metabolomic characterization of Pseudomonas protegens secretions for identification of biopesticides against Bacterial Panicle Blight of rice
Tuesday, April 5, 2022
12:30 PM – 1:45 PM
Location: Exhibit/Poster Hall A-B - Pennsylvania Convention Center
Poster Board Number: A364
Samantha Balboa (University of North Carolina at Chapel Hill), Maia Vierengel (University of North Carolina at Chapel Hill), Kristen Gates (University of Arkansas), Clemencia Rojas (University of Arkansas), Leslie Hicks (University of North Carolina at Chapel Hill)
Presenting Author University of North Carolina at Chapel Hill
Bacterial Panicle Blight (BPB) is a rice disease caused by Burkholderia glumae that has become a global concern in reducing rice yields. Currently, there are no effective chemical treatments or resistant cultivars to control BPB. We have observed that bacterial secreted fractions from the antagonistic microorganism Pseudomonas protegens PBL3 inhibits B. glumae infections in rice plants. However, the responsible antimicrobial molecules are unknown. Genome comparison between P. protegens PBL3 and the reference strain P. protegens CHA0, a well-characterized microbial biological control agent, revealed the presence of 14 known biosynthetic gene clusters (BGCs) in P. protegens PBL3. From this genomic data, it is likely that P. protegens PBL3 secretes metabolites with activity against BPB that are not produced by P. protegens CHA0.
Cultures of P. protegens PBL3 and the reference strain, P. protegens CHA0, were grown in M9 minimal media supplemented with 1% myo-inositol. The metabolite secretome of P. protegens PBL3 and CHA0 were harvested in log phase and analyzed with a Waters Acquity H-Class HPLC coupled to a Thermo Q-Exactive HF-X. In addition, active PBL3 fractions against B. glumae were analyzed via LC-MS to confirm the presence of bioactive compounds. The resulting data were searched against the Global Natural Products Social Molecular Networking (GNPS) spectral library. For potential antimicrobial peptide identification, data were searched against the Mascot database. To validate these results, known bioactive metabolites in P. protegens CHA0 were identified. By utilizing LC-MS/MS based metabolomics, several compounds were uniquely identified in P. protegens PBL3 that could be used as biocontrol agents against BPB in rice.
