Characterization of the wheat cultivars against Tilletia controversa Kühn, causal agent of wheat dwarf bunt

Abstract

Wheat is one of the most important staple crops. Tilletia controversa Kühn is the causal agent of wheat dwarf bunt. In this study, a resistant wheat cultivar displayed significantly higher expression of pathogenesis-related genes than a susceptible cultivar at 7 days post inoculation (DPI) with T. controversa. Similarly, the expression was high in the resistant cultivar after exogenous application of phytohormones, including salicylic acid. The expression of pathogenesis-related genes, especially chitinase 4, was high in the resistant cultivar, while LPT-1 was down regulated after T. controversa infection. Callose deposition was greater in the resistant cultivar than in the susceptible cultivar at 10 DPI. Confocal microscopy was used to track the fungal hyphae in both cultivars in anther and ovary cells. The anthers and ovaries of the susceptible cultivar were infected by T. controversa at 7 and 15 DPI. There were no fungal hyphae in anther and ovary cells in the resistant cultivar until 10 and 23 DPI, respectively. Moreover, anther length and width were negatively influenced by T. controversa at 16 DPI. The plant height was also affected by fungal infection. Ultimately, resistance to T. controversa was achieved in cultivars via the regulation of the expression of defense-related and pathogenesis-related genes.