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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #322119
Title: Identification of a signal that mediates the crosstalk between biosynthetic gene clusters for the antibiotics 2,4-diacetylphloroglucinol and pyoluteorin in Pseudomonas protegens Pf-5

Author
item YAN, QING - Oregon State University
item Clifford, Jennifer
item PHILMUS, BENJAMIN - Oregon State University
item CHANG, JEFF - Oregon State University
item Loper, Joyce

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/2/2015
Publication Date: 6/16/2015
Citation: Yan, Q., Clifford, J.M., Philmus, B., Chang, J.H., Loper, J.E. 2015. Identification of a signal that mediates the crosstalk between biosynthetic gene clusters for the antibiotics 2,4-diacetylphloroglucinol and pyoluteorin in Pseudomonas protegens Pf-5 [abstract]. 10th International PGPR Workshop.

Interpretive Summary:

Technical Abstract: Pseudomonas protegens Pf-5 produces at least seven secondary metabolites with anti-microbial activity. The production of two of these metabolites, 2,4-diacetylphloroglucinol (2,4-DAPG) and pyoluteorin, is coordinately regulated. Each of the two metabolites functions as an intercellular signal, inducing the expression of genes responsible for its own biosynthesis, but mechanisms involved in cross talk between the two pathways remain obscure. Here, we report that phloroglucinol, an intermediate in the synthesis of 2,4-DAPG, regulated the transcription of genes in the pyoluteorin biosynthesis cluster in a concentration-dependent manner. Low Positive regulation of the pyoluteorin biosynthesis gene pltA by the linked transcriptional regulator PltR required phloroglucinol (100 nM) and was abolished by a mutation in pltM, which encodes a putative halogenase. A pltM mutant of Pf-5 did not produce pyoluteorin or express pltA, even in the presence of phloroglucinol. Purified PltM converted phloroglucinol into a new compound in vitro. This compound induced pltA expression in a pltM deficient strain. The chemical structure of the compound is being determined, and initial results indicate that it is a chlorinated derivative of phloroglucinol. Taken together, our data suggest that phloroglucinol was processed by PltM into a chlorinated derivative, which functions as an intercellular signal regulating pyoluteorin gene expression.