Identification of Candidate Genes for a Major Quantitative Disease Resistance Locus from PI 427105B for Resistance to Phytophthora sojae

In this study, high resolution mapping reduced the QDRL interval to 3.1 cM, and RNA-seq analysis of near-isogenic lines (NILs) varying at QDRL-18 pinpointed a single gene of interest which was downregulated in inoculated NILs carrying the resistant allele compared to inoculated NILs with the susceptible allele at all time points. This gene of interest putatively encodes a serine threonine kinase (STK) related to the AtCR4 family, and may be acting as a susceptibility factor, based on the specific increase of jasmonic acid concentration in inoculated NILs. This work facilitates further functional analyses and marker-assisted breeding efforts by prioritizing candidate genes and narrowing the targeted region for introgression.