Engineering Fusarium head blight resistance in wheat by expression of a fusion protein containing a Fusarium-specific antibody and an antifungal peptide

Fusarium head blight (FHB) or scab of wheat is a devastating disease in warm and humid regions at wheat-flowering periods worldwide. Natural resistance against FHB pathogens is inadequate and the development of FHB-resistant wheat cultivars has been a challenge. Expression of pathogen-specific antibodies in plants has been proposed as a strategy for crop protection. In this study, an antibody fusion protein comprising a Fusarium-specific recombinant antibody derived from chicken and an antifungal peptide from Aspergillus giganteus was expressed in wheat as a method for protecting plants against FHB pathogens. Plants expressing the antibody fusion displayed a very significantly enhanced resistance in T2 and T3 generations upon single-floret inoculation with the macroconidia of Fusarium asiaticum, the predominant species causing FHB in China, indicating a type II resistance. Spraying inoculation further revealed an enhanced type I resistance in the transgenic wheat plants. Remarkably, more grains were produced in the transgenic plants than the nontransgenic controls. Our results demonstrated that the antibody fusion protein may be used as an effective tool for the protection of crops against FHB pathogens.