|Seong, Kyeyong - PURDUE UNIVERSITY|
|Tracy, Miles - PURDUE UNIVERSITY|
|Xu, Jinrong - PURDUE UNIVERSITY|
Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 13, 2003
Publication Date: December 13, 2003
Citation: Seong, K., Tracy, M., Kistler, H.C., Xu, J. 2003. REMI mutagenesis in Fusarium graminearum [abstract]. 2003 National Fusarium Head Blight Forum Proceedings, December 12-15, 2003, Bloomington, Minnesota. p. 177. Technical Abstract: Fusarium graminearum is an important pathogen of small grains and maize in many areas of the world. Infected grains are often contaminated with mycotoxins harmful to humans and animals. To better understand the molecular mechanism of plant infection and virulence of F. graminearum, we used the REMI (Restriction-Enzyme Mediated Integration) approach to generate random targeted mutants. Over 9,000 hygromycin-resistant transformants have been generated in the wild-type strain PH-1. Genes disrupted in two of these REMI mutants were recovered by plasmid rescue. In mutant 222, the transforming vector was integrated at the 268 amino acid of the hydroxymethylglutaryl CoA reductase gene (HMR1) that is essential for lipid biosynthesis. Disruption of HMR1 significantly reduced the growth rate and aerial hyphal development in F. graminearum. Mutant 222 was non-pathogenic on flowering wheat heads and produced hyper-branching hyphae that are wider in diameter than that of the wild type strain PH-1. In mutant M8, the plasmid was integrated in the promoter region (110 bp upstream) of the cystathionine beta-lyase gene (CBL1). Mutant M8 had normal growth rate but produced rare aerial hyphae. Its virulence was significantly reduced. Gene replacement mutants deleted of CBL1 had phenotypes identical to that of REMI mutant M8. Further characterization of the HMR1 and CBL1 genes will be presented.