A deletion mutation in TaHRC confers Fhb1 resistance to Fusarium head blight in wheat.

Fusarium head blight (FHB)， which is mainly caused by Fusarium graminearum， is a destructive wheat disease that threatens global wheat production. Fhb1， a quantitative trait locus discovered in Chinese germplasm， provides the most stable and the largest effect on FHB resistance in wheat. Here we show that TaHRC， a gene that encodes a putative histidine-rich calcium-binding protein， is the key determinant of Fhb1-mediated resistance to FHB. We demonstrate that TaHRC encodes a nuclear protein conferring FHB susceptibility and that a deletion spanning the start codon of this gene results in FHB resistance. Identical sequences of the TaHRC-R allele in diverse accessions indicate that Fhb1 had a single origin， and phylogenetic and haplotype analyses suggest that the TaHRC-R allele most likely originated from a line carrying the Dahongpao haplotype. This discovery opens a new avenue to improve FHB resistance in wheat， and possibly in other cereal crops， by manipulating TaHRC sequence through bioengineering approaches.