title: Diversities in virulence, antifungal activity, pigmentation and DNA fingerprint among strains of Burkholderia glumae.
abstract: Burkholderia glumae is the primary causal agent of bacterial panicle blight of rice. In this study, 11 naturally avirulent and nine virulent strains of B. glumae native to the southern United States were characterized in terms of virulence in rice and onion, toxofalvin production, antifungal activity, pigmentation and genomic structure. Virulence of B. glumae strains on rice panicles was highly correlated to virulence on onion bulb scales, suggesting that onion bulb can be a convenient alternative host system to efficiently determine the virulence of B. glumae strains. Production of toxoflavin, the phytotoxin that functions as a major virulence factor, was closely associated with the virulence phenotypes of B. glumae strains in rice. Some strains of B. glumae showed various levels of antifungal activity against Rhizoctonia solani, the causal agent of sheath blight, and pigmentation phenotypes on casamino acid-peptone-glucose (CPG) agar plates regardless of their virulence traits. Purple and yellow-green pigments were partially purified from a pigmenting strain of B. glumae, 411gr-6, and the purple pigment fraction showed a strong antifungal activity against Collectotrichum orbiculare. Genetic variations were detected among the B. glumae strains from DNA fingerprinting analyses by repetitive element sequence-based PCR (rep-PCR) for BOX-A1R-based repetitive extragenic palindromic (BOX) or enterobacterial repetitive intergenic consensus (ERIC) sequences of bacteria; and close genetic relatedness among virulent but pigment-deficient strains were revealed by clustering analyses of DNA fingerprints from BOX-and ERIC-PCR.
authors.affiliation: Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America.
authors.forename: Hari S
authors.initials: HS
authors.lastname: Karki
authors.forename: Bishnu K
authors.initials: BK
authors.lastname: Shrestha
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Han
authors.forename: Donald E
authors.initials: DE
authors.lastname: Groth
authors.forename: Inderjit K
authors.initials: IK
authors.lastname: Barphagha
authors.forename: Milton C
authors.initials: MC
authors.lastname: Rush
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Melanson
authors.forename: Beom Seok
authors.initials: BS
authors.lastname: Kim
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Ham
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology; D019117:Burkholderia / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity* / Q000502:physiology; D016172:DNA Fingerprinting; D019697:Onions / Q000382:microbiology; D010858:Pigmentation / Q000502:physiology*; D011744:Pyrimidinones / Q000378:metabolism; D012232:Rhizoctonia / Q000254:growth & development; D014227:Triazines / Q000378:metabolism; D014774:Virulence / Q000235:genetics
chemical_list: D000935:Antifungal Agents; D011744:Pyrimidinones; D014227:Triazines; C009570:toxoflavin