Eukaryotic Cell
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Idnurm, A.
Right arrow Articles by Howlett, B. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Idnurm, A.
Right arrow Articles by Howlett, B. J.

 Previous Article  |  Next Article 

Eukaryotic Cell, October 2002, p. 719-724, Vol. 1, No. 5
1535-9778/02/$04.00+0     DOI: 10.1128/EC.1.5.719-724.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Isocitrate Lyase Is Essential for Pathogenicity of the Fungus Leptosphaeria maculans to Canola (Brassica napus)

Alexander Idnurm and Barbara J. Howlett*

School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia

Received 17 June 2002/ Accepted 29 July 2002

A pathogenicity gene has been identified in Leptosphaeria maculans, the ascomycetous fungus that causes blackleg disease of canola (Brassica napus). This gene encodes isocitrate lyase, a component of the glyoxylate cycle, and is essential for the successful colonization of B. napus. It was identified by a reverse genetics approach whereby a plasmid conferring hygromycin resistance was inserted randomly into the L. maculans genome. Twelve of 516 transformants tested had reduced pathogenicity on cotyledons of B. juncea and B. napus, and 1 of these 12 had a deletion of the isocitrate lyase gene, as well as an insertion of the hygromycin resistance gene. This mutant was unable to grow on fatty acids, including monolaurate, and the isocitrate lyase transcript was not detected. When the wild-type gene was reintroduced into the mutant, growth on monolaurate was restored and pathogenicity was partially restored. L. maculans isocitrate lyase is produced during infection of B. napus cotyledons, while the plant homologue is not. When 2.5% glucose was added to the inoculum of the isocitrate lyase mutant, lesions of sizes similar to those caused by wild-type isolate M1 developed on B. napus cotyledons. These findings suggest that the glyoxylate pathway is essential for disease development by this plant-pathogenic fungus, as has been shown recently for a fungal and bacterial pathogen of animals and a bacterial pathogen of plants. Involvement of the glyoxylate pathway in pathogenesis in animals and plants presents potential drug targets for control of diseases.

* Corresponding author. Mailing address: School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia. Phone: 61 3 8344 5062. Fax: 61 3 9347 1071. E-mail: bhowlett{at}unimelb.edu.au.

Eukaryotic Cell, October 2002, p. 719-724, Vol. 1, No. 5
1535-9778/02/$04.00+0     DOI: 10.1128/EC.1.5.719-724.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Appl. Environ. Microbiol. Infect. Immun. J. Bacteriol.
Mol. Cell Biol. Microbiol. Mol. Biol. Rev. ALL ASM JOURNALS
Copyright © 2002 by the American Society for Microbiology.