Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2008
Publication Date: 12/2/2008
Citation: Menke, J., Dong, Y., Kistler, H.C. 2008. Comparative Gene Expression Analysis of Fusarium graminearum in Triticum aestivum and Oryza sativa spp. japonica. National Fusarium Head Blight Forum Proceedings. 57.
Technical Abstract: Negligible amounts of Type B trichothecenes accumulate in Oryza sativa spp. japonica infected with Fusarium graminearum relative to Triticum aestivum inoculated with an identical strain of the fungus. To identify differential fungal gene expression patterns that could be responsible for differences in toxin accumulation in these plants, analyses of expression were conducted during infection of O. sativa or T. aestivum using F. graminearum Affymetrix GeneChips. Gene expression profiles were generated for time points 48, 96, and 192 hours after inoculation (hai) of plants. Profile analyses revealed a subset of genes (236) expressed only in T. aestivum. Classification of these genes using MIPs FunCat categories showed 110 of these genes fell into the Unclassified category. Five of these genes encode InterPRO predicted zinc-finger transcription factors and are being targeted for functional analysis via gene knock-out mutagenesis. Sixty-three genes fell into the Metabolism category, the next highest representation among the remaining genes. An in silico search of non-coding upstream regions for regulatory sequences in all 236 genes revealed an enrichment of two nucleotide sequences: ACGTCA and CCCCGC. Differences in temporal patterns of global fungal gene expression were observed during infections of the different hosts. In T. aestivum, expression levels of all genes increased from time point to successive time point, whereas expression levels of genes in O. sativa remained relatively constant. These results were well correlated with symptoms observed on both plants. Onset of symptoms first occurred on O. sativa at 48 hai and slowly increased in severity over time. Symptoms were first observed on T. aestivum 72 hai and intensified continuously and more quickly than those observed on O. sativa.