Location: Toxicology and Mycotoxin Research
Title: Identification and analysis of Fusarium verticillioides genes differentially expressed during conidiation Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 14, 2011
Publication Date: March 14, 2011
Citation: Burnham, A., Brown, D.W., Glenn, A.E. 2011. Identification and analysis of Fusarium verticillioides genes differentially expressed during conidiation. Georgia Association of Plant Pathologists. Mar. 14-16,2011. Pine Mountain, GA, Technical Abstract: Fusarium verticillioides, an endophytic maize pathogen, is the causal agent of diseases, such as ear rot, seedling blight, and stalk rot, resulting in major economic losses in maize production. This fungus can also cause certain diseases in animals due to consumption of feed contaminated with fumonisin mycotoxins. F. verticillioides produces abundant microconidia in long chains from the apex of phialides. These conidia are essential for the infection of the crop. Upon mating two previously characterized, conidia-producing strains, MRC 826 and NRRL 25029, spontaneous mutations occurred resulting in half of the progeny being unable to produce conidia. These mutants produced germ tube-like growths from the tips of phialides instead of normal enteroblastic production of conidia. Based on microarray data comparing MRC 826 (wild-type strain) and AEG 3-A3-5 (aconidial mutant), thirteen candidate genes having at least 10-fold change in expression in the wild-type strain were chosen for further analysis. One of the thirteen, FVEG_10983, has been targeted for gene deletion because of its 72-fold change. FVEG_10983 has no homology to previously characterized proteins and no obvious protein domains. BLAST searches showed significant similarity only to other filamentous fungi including one homolog from F. oxysporum and three from F. graminearum. Microscopy analyses of FVEG_10983 knockouts show the possible loss of a unique characteristic for F. verticillioides which is the production of conidia in long chains from the tip of the phialide. This suggests FVEG_10983 may be involved in phialide development or cell wall formation. To address this hypothesis, phenotypic analyses will allow morphological changes to be observed in order to proceed in the characterization of this gene. Further analysis of FVEG_10983 and the other genes may identify novel characteristics of sporulation in F. verticillioides.