Description
The maize smut fungus, Sporisorium reilianum f. sp. zeae, which is an important biotrophic pathogen responsible for extensive crop losses, infects maize by invading the root during the early seedling stage. In order to investigate disease-resistance mechanisms at this early seedling stage, digital gene expression (DGE) analysis, which applies a dual-enzyme approach (DpnII and NlaIII), was used to identify the transcriptional changes in roots of Huangzao4 (susceptible) and Mo17 (resistant) after inoculation with teliospores of S. reilianum. Before and after inoculation, pathogenesis-related genes were differentially regulated and enzymes involved in controlling reactive oxygen species (ROS) levels showed different activity between Huangzao4 and Mo17, which can potentially lead to changes in the growth of S. reilianum and ROS production in maize. Moreover, lignin depositions of roots were also changed differentially during root colonization of hyphae between Huangzao4 and Mo17. These results suggest that the interplays between S. reilianum and maize during the early infection stage involve many interesting transcriptional and physiological changes, which offer several novel insights for understanding the mechanisms of resistance to the fungal infection. Overall design: Examination of control stage (ck), post-inoculation stage1 (P1) and post-inoculation stage2 (P2) in Huangzao4 (susceptible) and Mo17 (resistant)