Differential analysis of Ht2-related genes in incompatible reaction between Huangzaosi Ht2 and Exserohilum turcicum race 1

cDNA amplified fragment length polymorphism (cDNA-AFLP) was conducted to analyze dif-ferential expression of Ht2-related genes between near-isogenic lines (NILs) Huangzaosi (HZS) and HuangzaosiHt2 (HZSHt2) after inoculation with race 1 of Exserohilum turcicum. Seventy-six transcript-derived fragments (TDFs),designated Ex01 to Ex76,were specifically expressed in HZSHt2. BLAST analysis showed that 52 of them were homologous to the genes in the GenBank database. The TDFs with significant protein homology were classified into eight functional categories:basal energy metabolism,transmembrane transport protein,defense/resistance protein,protein metabolism,protein of chromosome and proteins of DNA replication and transcription,signal transduction,growing development mediator and transcription factor. Most of these genes were associated with basal energy metabolism and defence/resistance gene.Analyzing the space-time trait of 52 TDFs showed that they were ranged from chromosome 1 to 9. Signal transduction genes expressed at 6 h after inoculation and defense/resistance genes started to express at 48-72 h. Ht2-related gene expressions profiling in response to inoculation of E. turcicum were analyzed by means of cDNA-AFLP. The identification of Ht2-related genes in the study are important for further study of Ht2 gene and the mechanism of resistance to E. turcicum in maize.