Isolation and Identification of Differentially Expressed Genes in Sugarcane Infected by Ustilago scitaminea

The objective of this study was to survey the molecular mechanism of resistance to sugarcane smut (Ustilago scitaminea Syd.). Two sugarcane (Saccharum officinarum complex) varieties NCo376 with high resistance and F134 with susceptibility were infected by U. scitaminea and the genes associated with the smut resistance were detected with 12 anchored primers and 8 random primers via differential display reverse transcription PCR (DDRT-PCR). Seven differentially expressed fragments were obtained through cloning, sequencing, and semiquantitative RT-PCR validation. The results of Blast in GenBank showed that they shared high homology (35–99%) with cytochrome C oxidase (CCO) gene, ribosomal protein gene, NAD-dependent malic enzyme gene, aminotransferase gene, binding protein gene, RNA polymerase specific transcription initation factor and retrotransposon. The results of semiquantitative RT-PCR showed that CCO gene expression was regulated by U. scitaminea and salicylic acid, and was independent of H2O2. Besides, CCO gene was expressed in root, stalk, and leaf of sugarcane at relatively low levels. Thereby, the phytoalexin induced by CCO gene was inferred to inhibit the pathogen after infection.