Expression of a truncated form of yeast ribosomal protein L3 in transgenic wheat improves resistance to Fusarium head blight

Fusarium head blight (FHB) is a disease that causes major economic losses in wheat and barley production worldwide. Contamination of food with the trichothecene mycotoxin deoxynivalenol (DON) produced by Fusarium is a major health concern for humans and animals because trichothecenes are potent cytotoxins of eukaryotic cells. Trichothecene mycotoxins inhibit translation by targeting ribosomal protein L3 at the peptidyltransferase center. We previously showed that expression of an N-terminal fragment of yeast L3 (L3Δ) in transgenic tobacco plants reduced the toxicity of DON. Here, we produced transgenic wheat plants that express the same yeast L3 (L3Δ) fragment and evaluated their susceptibility to Fusarium graminearum infection and their ability to accumulate DON. Following F. graminearum infection in greenhouse tests, two transgenic wheat lines expressing the highest levels of L3Δ showed reductions in disease severity and kernel DON levels, compared to non-transformed plants. In a field test, a transgenic wheat line with the highest L3Δ expression controlled by the maize Ubi1 promoter had significant reductions in visually scabby kernels and kernel DON levels. These results demonstrate that expression of a modified form of the ribosomal protein that is the target of DON can improve FHB resistance in wheat.