Evolution of host resistance in a toxin-producing bacterial-fungal alliance

The rice seedling blight fungus Rhizopus microsporus harbors endosymbiotic Burkholderia sp. for the production of the virulence factor, the antimitotic agent rhizoxin. Since the toxin highly efficiently blocks mitosis in most eukaryotes, it remained elusive how self-resistance emerged in the fungal...

Full description

Saved in:

Bibliographic Details
Published in:	The ISME Journal Vol. 2; no. 6; pp. 632 - 641
Main Authors:	Schmitt, Imke, Partida-Martinez, Laila P, Winkler, Robert, Voigt, Kerstin, Einax, Esra, Dölz, Franziska, Telle, Sabine, Wöstemeyer, Johannes, Hertweck, Christian
Format:	Journal Article
Language:	English
Published:	London Nature Publishing Group UK 01-06-2008 Nature Publishing Group
Subjects:	Amino Acid Sequence Amino acids Aquatic plants Ascomycota Bacteria Bacterial Toxins - chemistry Bacterial Toxins - metabolism Bacterial Toxins - pharmacology Biomedical and Life Sciences Burkholderia Burkholderia - physiology Drug Resistance, Fungal Ecology Evolution, Molecular Evolutionary Biology Fungal Proteins - chemistry Fungal Proteins - genetics Fungal Proteins - metabolism Fungi - classification Fungi - drug effects Fungi - genetics Life Sciences Macrolides - chemistry Macrolides - metabolism Macrolides - pharmacology Microbial Ecology Microbial Genetics and Genomics Microbiology Models, Molecular Molecular Sequence Data Mutualism original-article Oryza sativa Parasitism Phylogeny Protein Binding Rhizopus - drug effects Rhizopus - genetics Rhizopus - physiology Rhizopus microsporus Seedlings Symbiosis Toxins Tubulin - chemistry Tubulin - genetics Tubulin - metabolism Zygomycota tubulin evolution fungi symbiosis
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The rice seedling blight fungus Rhizopus microsporus harbors endosymbiotic Burkholderia sp. for the production of the virulence factor, the antimitotic agent rhizoxin. Since the toxin highly efficiently blocks mitosis in most eukaryotes, it remained elusive how self-resistance emerged in the fungal host. In this study, rhizoxin sensitivity was systematically correlated with the nature of β-tubulin sequences in the kingdom Fungi. A total of 49 new β-tubulin sequences were generated for representative species of Ascomycota, Basidiomycota and Zygomycota. Rhizoxin sensitivity assays revealed two further amino acids at position 100 (Ser-100 and Ala-100), in addition to the known Ile-100 and Val-100, which convey rhizoxin resistance. All sensitive strains feature Asn-100. This hot spot was verified by modeling studies, which support the finding that rhizoxin preferentially interacts with the tubulin molecule in a cavity near position 100. Ancestral character state reconstructions conducted in a Bayesian framework suggest that rhizoxin sensitivity represents the ancestral character state in fungi, and that evolution of rhizoxin resistance took place in the ancestor of extant resistant Zygomycota. These findings support a model according to which endosymbiosis became possible through a parasitism—mutualism shift in insensitive fungi.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	1751-7362 1751-7370
DOI:	10.1038/ismej.2008.19