Differential Synthesis of Peritoxins and Precursors by Pathogenic Strains of the Fungus Periconia circinata

AUTOR(ES)

Churchill, Alice C. L.

FONTE

American Society for Microbiology

RESUMO

Pathogenic strains of the soilborne fungus Periconia circinata produce peritoxins with host-selective toxicity against susceptible genotypes of sorghum. The peritoxins are low-molecular-weight, hybrid molecules consisting of a peptide and a chlorinated polyketide. Culture fluids from pathogenic, toxin-producing (Tox+) and nonpathogenic, non-toxin-producing (Tox−) strains were analyzed directly by gradient high-performance liquid chromatography (HPLC) with photodiode array detection and HPLC-mass spectrometry to detect intermediates and final products of the biosynthetic pathway. This approach allowed us to compare the metabolite profiles of Tox+ and Tox− strains. Peritoxins A and B and the biologically inactive intermediates, N-3-(E-pentenyl)-glutaroyl-aspartate, circinatin, and 7-chlorocircinatin, were detected only in culture fluids of the Tox+ strains. The latter two compounds were produced consistently by Tox+ strains regardless of the amount of peritoxins produced under various culture conditions. In summary, none of the known peritoxin-related metabolites were detected in Tox− strains, which suggests that these strains may lack one or more functional genes required for peritoxin biosynthesis.

Documentos Relacionados

• Structure of the host-specific toxins produced by the fungal pathogen Periconia circinata.
• Alterations in gene expression in sorghum induced by the host-specific toxin from Periconia circinata
• Antibiosis of Trichoderma spp strains native to northeastern Mexico against the pathogenic fungus Macrophomina phaseolina
• Proteinase production by the parasitic cycle of the pathogenic fungus Coccidioides immitis.
• Candida Albicans: The Pathogenic Fungus