A Sequence Deletion in HRC-like Gene Confers Fhb1 Resistance to Fusarium Head Blight in Wheat

Fusarium head blight (FHB) is a destructive disease of wheat and prevalence of FHB epidemics in recent years threatens global wheat production. Fhb1 is the quantitative trait locus that shows the largest effect on FHB resistance in wheat, but its gene identity remains unknown. Here, the gene underlying Fhb1, a putative histidine-rich calcium-binding protein (TaHRC), was identified by the integration of forward and reverse genetic approaches. Loss of function mutation of TaHRC confers FHB resistance indicated it acts as a susceptible factor for FHB spreading in spike. Identical sequence of TaHRC resistance allele indicated it derived from the same mutation variation. Haplotype and sequence analysis in the candidate gene region of Fhb1 indicated the loss-of-function mutation of Fhb1 was derived from one of the Chinese landrace cluster, Dahongpao. Genotyping the world informative core collection accession with the causal diagnose marker of Fhb1 showed its resistance allele only present in China and Japanese, indicated the Fhb1 derived from eastern Asia. TaHRC encodes an uncharacterized nucleic protein, suggesting that it is a new type of genes for plant disease resistance. Cloning of Fhb1 opens a new door to defeating wheat FHB by manipulating TaHRC levels using marker-assisted breeding and bioengineering approaches.