The production of 2,4-diacetylphloroglucinol (DAPG) by the biocontrol agent Pseudomonas fluorescens Pf-5 was studied in nutrient-solution based media with varying nitrogen content. No production of DAPG was observed when organic nitrogen was omitted from the media, regardless of the inorganic nitrogen source used. Furthermore, a micromolar concentration range of organic nitrogen was insufficien...

The 2,4-Diacetylphloroglucinol (2,4-DAPG) and phenazine (PCA)-producing Pseudomonas inhibit wheat pathogens’ development, but the relationship between communities of pathogens genotypes these bacteria has been little studied. Relationships crown fungi associated with presence 2,4-DAPG PCA-producing pseudomonads were evaluated in four commercial crops located La Araucanía Los Lagos Regions Chile...

The aim of this work was to determine the effect of wild type and functionally modified Pseudomonas fluorescens strains on C fractions in the rhizosphere of pea. The lacZY marked F113 strain produces the antibiotic 2,4 diacetylphloroglucinol (DAPG) useful in plant disease control. The modified strain of F113 was repressed in production of DAPG, creating the DAPG negative strain F113 G22. The F1...

Plants have evolved strategies of stimulating and supporting specific groups of antagonistic microorganisms in the rhizosphere as a defense against diseases caused by soilborne plant pathogens owing to a lack of genetic resistance to some of the most common and widespread soilborne pathogens. Some of the best examples of natural microbial defense of plant roots occur in disease suppressive soil...

Kwak, Y.-S., Bakker, P. A. H. M., Glandorf, D. C. M., Rice, J. T., Paulitz, T. C., and Weller, D. M. 2009. Diversity, virulence, and 2,4-diacetylphloroglucinol sensitivity of Gaeumannomyces graminis var. tritici isolates from Washington State. Phytopathology 99:472-479. We determined whether isolates of the take-all pathogen Gaeumannomyces graminis var. tritici become less sensitive to 2,4-diac...

2, 4-Diacetylphloroglucinol (2,4-DAPG), a natural phenolic compound, has been investigated in light of its biological activities against plant pathogens. To improve its potential application, fourteen 2,4-DAPG analogous were synthesized through the Friedel-Crafts reaction using acyl chlorides and phloroglucinol. Of the 2,4-DAPG derivatives, MP4 exhibited much higher antifungal activity against ...

Sir, Methicillin-resistant Staphylococcus aureus (MRSA) causes serious public health problems throughout the world. Moreover, the susceptibility of MRSA to vancomycin, the ‘last resort’ antibiotic, has recently been shown to be reduced, necessitating the development of alternative post-vancomycin antibiotics and other chemotherapeutic agents. In a previous study to identify new types of antibac...

ABSTRACT Strains of Pseudomonas fluorescens producing the antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG) are biocontrol agents which play a key role in the suppressiveness of some soils against soilborne pathogens. We evaluated the effect of the host plant genotype on rhizosphere colonization by both indigenous and introduced 2,4-DAPG-producing P. fluorescens. First, population densities of i...

ABSTRACT Strains of fluorescent Pseudomonas spp. that produce the antibiotic 2,4-diacetylphoroglucinol (2,4-DAPG) are among the most effective rhizobacteria controlling diseases caused by soilborne pathogens. The genotypic diversity that exists among 2,4-DAPG producers can be exploited to improve rhizosphere competence and biocontrol activity. Knowing that D-genotype 2,4-DAPG-producing strains ...