The Soybean Rpp3 Gene Encodes a TIR-NBS-LRR Protein that Confers Resistance to Phakopsora pachyrhizi

Soybean rust is an economically significant disease caused by the fungus that negatively impacts soybean ( [L.] Merr.) production throughout the world. Susceptible plants infected by develop tan-colored lesions on the leaf surface that give rise to funnel-shaped uredinia as the disease progresses. While most soybean germplasm is susceptible, seven genetic loci ( to ) that provide race-specific resistance to ( ) have been identified. was first discovered and characterized in the soybean accession PI 462312 (Ankur), and it was also determined to be one of two genes present in PI 506764 (Hyuuga). Genetic crosses with PI 506764 were later used to fine-map the locus to a 371-kb region on chromosome 6. The corresponding region in the susceptible Williams 82 (Wm82) reference genome contains several homologous nucleotide binding site-leucine rich repeat (NBS-LRR) genes. To identify , we designed oligonucleotide primers to amplify ( ) NBS-LRR genes at this locus from PI 462312, PI 506764, and Wm82 using polymerase chain reaction (PCR). Five genes were identified in both -resistant soybean lines, and co-silencing these genes compromised resistance to . Gene expression analysis and sequence comparisons of the genes in PI 462312 and PI 506764 suggest that a single candidate gene, , is responsible for -mediated resistance. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2024.