Abstract: Fusarium head blight (FHB), also known as “wheat cancer”, which not only seriously damages the yield and quality of wheat, but also leads to the serious pollution of mycotoxins such as deoxynivalenol (DON) and nivalenol (NIV). Discovery and exploitation of new resistance genes to FHB is one of the most effective methods to resist pathogens infection. In this study, a major wheat FHB resistance gene Fhb7 was cloned based on assembling the genome of Thinopyrum elongatum and BAC library. Fhb7 encodes a glutathione S-transferase (GST) with broad-spectrum catalysis, which can detoxify the trichothecenes toxins through de-epoxidation mechanism. Surprisingly, no homologous genes of Fhb7 have been found in the plant kingdom, but multiple evidences indicate that Thinopyrum elongatum may form symbiosis with endophytic fungi of Epichloë genus in the early stage, and integrate the DNA sequence of Epichloë Fhb7 into the Thinopyrum elongatum genome throughhorizontal gene transfer (HGT), thereby evolving
the function of being resistant to infection by Fusarium pathogens. Fhb7 conferred broad-spectrum resistance to FHB and crown rot in
diverse wheat backgrounds without obvious penalty on yields or quality. Thus, Fhb7 has broad application prospects of wheat disease-resistant breeding.