Pathogenicity of Stagonospora nodorum requires malate synthase
Open Access
- 1 July 2004
- journal article
- Published by Wiley in Molecular Microbiology
- Vol. 53 (4), 1065-1073
- https://doi.org/10.1111/j.1365-2958.2004.04178.x
Abstract
A gene encoding malate synthase, a key enzyme of the glyoxylate cycle, has been cloned and characterized in the necrotrophic wheat pathogen Stagonospora nodorum. Expression studies of Mls1 showed high levels of transcript in ungerminated spores whereas malate synthase enzyme activities were low. Expression studies in planta found that Mls1 transcript levels decreased ≈ 10-fold upon germination before slowly increasing throughout the remainder of the infection. To characterize Mls1 further, the gene was disrupted in S. nodorum by homologous recombination. In the absence of any supplied carbon source, the mls1 spores were unable to germinate and consequently the mutants were non-pathogenic. Germination and pathogenicity could be restored by the addition of either glucose or sucrose, implying that S. nodorum is reliant upon the catabolism of lipids for infection. Furthermore, analysis of lipid bodies in the mutant strain indicated that lipid mobilization and, consequently, peroxisomal β-oxidation of fatty acids is delayed or inhibited by the disruption of the glyoxylate cycle. This study has demonstrated for the first time in a fungal phytopathogen the requirement of malate synthase for pathogenicity, suggesting that gluconeogenesis is both dependent on the glyoxylate cycle and required for infection.Keywords
This publication has 19 references indexed in Scilit:
- Isocitrate Lyase Is Essential for Pathogenicity of the Fungus Leptosphaeria maculans to Canola ( Brassica napus )Eukaryotic Cell, 2002
- Transcript Profiling in the Barley Mildew Pathogen Blumeria graminis by Serial Analysis of Gene Expression (SAGE)Molecular Plant-Microbe Interactions®, 2002
- Chromosomal Locus That Affects Pathogenicity of Rhodococcus fasciansJournal of Bacteriology, 2002
- Gene Identification in the Obligate Fungal Pathogen Blumeria graminis by Expressed Sequence Tag AnalysisFungal Genetics and Biology, 2001
- MAP Kinase and Protein Kinase A–Dependent Mobilization of Triacylglycerol and Glycogen during Appressorium Turgor Generation by Magnaporthe griseaPlant Cell, 2000
- Differential stress gene expression during the development ofNeurospora crassaand other fungiFEMS Microbiology Letters, 1998
- Expressed Sequences from Conidial, Mycelial, and Sexual Stages ofNeurospora crassaFungal Genetics and Biology, 1997
- Occurrence of the Glyoxylate Cycle in Basidiospores of HomobasidiomycetesMycologia, 1991
- A whole leaf clearing and staining technique for host specificity studies of rust fungiPlant Pathology, 1983
- Microbodies in Plant Pathogenic FungiAnnual Review of Phytopathology, 1977