Comparative Digital Gene Expression Analysis of Tissue-Cultured Plantlets of Highly Resistant and Susceptible Banana Cultivarsin Response to Fusarium oxysporum.

Banana wilt caused by f. sp. () is one of the most destructive soil-borne diseases. In this study, young tissue-cultured plantlets of banana ( spp. AAA) cultivars differing in susceptibility were used to reveal their differential responses to this pathogen using digital gene expression (DGE). Data were evaluated by various bioinformatic tools (Venn diagrams, gene ontology (GO) annotation and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses) and immunofluorescence labelling method to support the identification of gene candidates determining the resistance of banana against . Interestingly, we have identified as an important gene involved in both constitutive and induced resistance. We also identified new genes involved in the resistance of banana to , including several other transcription factors (TFs), pathogenesis-related () genes and some genes related to the plant cell wall biosynthesis or degradation (e.g., pectinesterases, β-glucosidases, xyloglucan endotransglucosylase/hydrolase and endoglucanase). The resistant banana cultivar shows activation of and genes as well as formation of different constitutive cell barriers to restrict spreading of the pathogen. These data suggest new mechanisms of banana resistance to .