Expression profiling and evolution of pathogenesis related genes in maize and teosinte in response to Ustilago maydis
S. CHAVAN (1), S. M. Smith (1). (1) University of Georgia, Athens, GA, U.S.A.
<i>Ustilago maydis</i> (<i>U. maydis</i>), the causal agent of corn smut, is an important agricultural pathogen and causes significant yield losses of approximately $1.5 billion annually in the United States. Several methods are currently used to control corn smut; however host resistance is the only practical method for managing smut. To identify genes controlling resistance to corn smut, transcriptome profiling was conducted in maize genotypes showing high levels of resistance and susceptibility against <i>U. maydis.</i> Maize, teosinte and 40 maize teosinte near Isogenic lines (NILs) were inoculated with a strain of <i>U. maydis</i>. Two teosinte lines and three NILs demonstrated a high level of resistance and a phenotypic response similar to maize. A total of 5,639 genes demonstrated significant differential expression between inoculated and uninoculated maize lines. From this data set, 529 genes were up-regulated (≥ 1.5 fold change), whereas 5,110 were down-regulated (≤ 1.5 fold change) in inoculated resistant and susceptible maize plants, respectively. The 529 up regulated genes and 5,110 down regulated genes were grouped into 8 functional categories. These included; biotic stress, enzyme families, receptor like kinases photosynthesis, metabolism and transcription. This work represents the first report of new potential sources of resistance to <i>U. maydis</i> from the wild progenitor (teosinte) and provides novel insight into the complexity of biotrophic interactions.
View Presentation |
