A Unique Expression Profile Responding to Powdery Mildew in Wild Emmer Wheat D430

Powdery mildew, caused by <i>Blumeria graminis</i> f. sp. <i>tritici</i> (<i>Bgt</i>), is a disease that seriously harms wheat production and occurs in all wheat-producing areas around the world. Exploring <i>Pm</i> gene(s) and developing resistant cultivars are preferred to control the disease. Wild emmer wheat (<i>Triticum dicoccoides</i>, 2n = 4x = 28, AABB) has accumulated abundant gene resources for resistance to powdery mildew during the long process of natural evolution. In the current study, the WEW accession D430 was highly resistant to powdery mildew at the whole-growth stage. Genetic analysis showed that the powdery mildew resistance in D430 was conferred by a single dominant locus or gene by the cross of D430 and susceptible durum wheat 647, tentatively named <i>PmD430</i>. Combining BSR-Seq analysis, molecular mapping, and sequence alignment, <i>PmD430</i> was finally mapped to <i>Pm4</i> locus, and the sequence was identical to <i>Pm4b</i>. Subsequently, 1871 DEGs between resistant and susceptible bulks were annotated and analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Eight disease-related genes were evaluated by qRT-PCR and exhibited a unique expression pattern when invaded by <i>Bgt</i> isolate E09 and was, therefore, presented as latent targets for regulating powdery mildew resistance in D430.