|Kistler, H - Corby|
Submitted to: PLoS Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2011
Publication Date: 12/22/2011
Citation: Wang, C., Zhang, S., Hou, R., Zheng, Q., Zhao, Z., Xu, Q., Zheng, D., Wang, G., Liu, H., Zhou, X., Ma, J., Kistler, H.C., Kang, Z., Xu, J. 2012. Functional analysis of the kinome of the wheat scab fungus Fusarium graminearum. PLoS Pathogens. 7(12):e1002460. Interpretive Summary: Fusarium head blight is among the most important diseases of wheat and barley world-wide. Highly effective and economical control measures for the disease are not currently available. We seek to develop new principles and measures for disease management by learning more about the spread and pathogenic adaptation of the fungus causing the disease. Several new genes for "master switches" controlling pathogenicity in the fungus were discovered by this work. Further knowledge of the genetic basis for pathogenicity may be used to develop alternative approaches to disease management and control. This information will be helpful to plant improvement specialists who are working to develop plants resistant to these pathogens or for developing novel strategies for disease control.
Technical Abstract: As in many other eukaryotes, protein kinases play major regulatory roles in filamentous fungi. Although the genomes of numerous plant pathogenic fungi have been sequenced, systematic characterization of their kinomes has not been reported. The wheat scab fungus Fusarium graminearum has 116 putative protein kinases (PK) genes. Although twenty of them appeared to be essential, we generated deletion mutants for the other 96 PK genes, including 12 orthologs of essential genes in budding yeast or fission yeast. All of the PK mutants were assayed for changes in 17 phenotypes, including vegetative growth, conidiation, plant infection, stress responses, and sexual reproduction. Related data were deposited in a searchable database (fgkinome.nwsuaf.edu.cn). Overall, deletion of 64 non-essential PK genes (66.7%) resulted in at least one of the phenotypes examined. Many of them had pleiotropic defects in growth, reproduction, and pathogenesis, and at least one mutant was identified for each phenotype examined, including three mutants blocked in conidiation and five mutants with increased tolerance to 0.7 M NaCl. In total, 42 PK mutants were significantly reduced in virulence or were non-pathogenic, including mutants deleted of key components of the cyclic adenylate monophosphate signaling and three mitogen-activated PK pathways. A number of these PK genes, such as FgMEC1 and FgSPS1, had no significant effect on normal hyphal growth and likely encode novel fungal virulence factors. Among 45 mutants defective in sexual reproduction, six of them formed perithecia but were aborted in ascus or ascospore development. Interestingly, F. graminearum contains two aurora kinase genes and two CDC2 genes that have distinct functions, which have not been reported in other fungi. In addition, we used the interlog approach to predict the PK-PK and PK-protein interaction networks of F. graminearum. Some of these predicted interactions were verified with yeast two-hybrid and co-immunoprecipitation assays. To our knowledge, this is the first functional characterization of the kinome in plant pathogenic fungi. Protein kinase genes important for various aspects of growth, developmental, and plant infection processes in F. graminearum were identified in this study.