Beticolins, nonpeptidic, polycyclic molecules produced by the phytopathogenic fungus Cercospora beticola, as a new family of ion channel-forming toxins

• Published in: Molecular plant-microbe interactions Vol. 13; no. 2; pp. 203 - 209
• Main Authors: GOUDET, C, MILAT, M.-L, SENTENAC, H, THIBAUD, J.-B
• Format: Journal Article
• Language: English
• Published: St Paul, MN APS Press 01.02.2000; American Phytopathological Society; The American Phytopathological Society
• Subjects: Ascomycota - pathogenicity; beticolins; Biochemistry, Molecular Biology; Biological and medical sciences; Cercospora beticola; Chenopodiaceae - microbiology; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Ion Channels - drug effects; Life Sciences; Lipid Bilayers; Mycotoxins - chemistry; Mycotoxins - toxicity; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - microbiology; Fungi; Toxin; Plant pathogen; Phytotoxin; Molecular structure; Cercospora beticola; Ionic channel; Berticolin; Fungi Imperfecti; Mechanism of action; Structure function relationship; Thallophyta; Probing alamethicin channels; phytotoxins; syringomycin-e; h+-atpase; biosurfactant; inhibition; water-soluble polymers; lipid bilayer-membranes; cell; conductance
• ISSN: 0894-0282; 1943-7706
• DOI: 10.1094/MPMI.2000.13.2.203

Beticolins are toxins produced by Cercospora beticola, a phytopathogenic fungus responsible for the leaf spot disease of sugar beet. They form a family of 20 nonpeptidic compounds (named B0 to B19) that share the same polycyclic skeleton but differ by isomeric configuration (ortho- or para-) and by a variable residue R (bridging two carbons in one of the six cycles). It has been previously shown that B0 assembles itself into a multimeric structure and forms ion channels into planar lipid bilayers (C. Goudet, A.-A. Very, M.-L. Milat, M. Ildefonse, J.-B. Thibaud, H. Sentenac, and J.-P. Blein, Plant J. 14:359-364, 1998). In the present work, we investigate pore formation by three ortho-beticolins, B0, B2, and B4, and their related (i.e., same R) para-isomers, B13, B1, and B3, respectively, using planar lipid bilayers. All beticolins were able to form ion channels with multiple conductance states, although the type of cyclization (ortho- or para-) and residue (R) result in variations of channel conductance and ionic permeability, respectively. Channel formation by beticolins is likely to be involved in the biological activity of these toxins.