|San Miguel, Phillip|
|Kistler, H - Corby|
Submitted to: Fungal Genetics and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/2002
Publication Date: 3/1/2003
Citation: TRAIL, F., XU, J., SAN MIGUEL, P., HALGREN, R.G., KISTLER, H.C. ANALYSIS OF EXPRESSED SEQUENCE TAGS FROM GIBBERELLA ZEAE (ANAMORPH FUSARIUM GRAMINEARUM). FUNGAL GENETICS AND BIOLOGY. 2003. v. 38. p. 187-197. Interpretive Summary: Fusarium graminearum, the cause of head blight disease of wheat and barley, has resulted in large economic loss to U.S. agriculture in the last decade. The fungus and the toxic compounds that it produces are hazards to food safety, as ingestion of infested grain is harmful to both humans and livestock. In order to learn more about how this fungus is able to cause disease, we have taken a genomics approach. Genomics is the science of heredity by which the overall genetic capacity (genome) of a living organism is studied by obtaining its total DNA sequence. In this paper we have obtained partial DNA sequences from more than 2,000 genes from the fungus that are expressed under environmental conditions that represent stages of the fungus that are important for disease. These DNA sequences, which amount to approximately 25% of the genes produced by the fungus, have been submitted to electronic databases so that they may be accessed by scientists worldwide. This information will be useful to other scientists who are seeking new ways to develop Fusarium-resistant wheat and barley because it potentially provides details of many genes required by the fungus in order to cause disease.
Technical Abstract: Fusarium graminearum is a broad host range pathogen that infects many crop plants, including wheat and barley, and causes head blight or rot diseases throughout the world. To better understand fungal development and pathogenicity in this important pathogen, we have now generated over 12,000 ESTs including 7996 ESTs from three cDNA libraries analyzed here. Two libraries were generated from carbon- (C-) and nitrogen- (N-) starved mycelia and one library was generated from cultures of maturing perithecia (P). In other fungal pathogens, starvation conditions have been shown to act as cues to induce infection-related gene expression. To assign putative function to cDNAs, sequences were initially assembled using StackPack into loose clusters and within these clusters, closely related ESTs were joined into contigs. From an input of 7996 EST sequences, 1088 contigs and 1022 singleton sequences were identified. Therefore, the estimated total number of genes identified from the three EST databases is 2110. These 2110 sequences were compared to a yeast protein sequence reference set and to the GenBank non-redundant database using BLASTX. Based on presumptive gene function, we found that the two starved cultures had similar, but not identical, patterns of gene expression, whereas the developmental cultures were distinct in their pattern of expression. Of the three libraries, the perithecium library had the greatest percentage (46%) of ESTS falling into the "unclassified" category. Homologs of some known fungal virulence or pathogenicity factors were found primarily in the N- and C- libraries. Comparisons also were made with ESTs from the related fungi, Neurospora crassa and Magnaporthe grisea.