ARS | Publication request: Isolation of an Yr5 candidate gene for resistance to wheat stripe rust

Submitted to: Plant and Animal Genome
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2006
Publication Date: January 2, 2007
Citation: Wang, M.N., Ling, P., Chen, X. 2007. Isolation of an Yr5 candidate gene for resistance to wheat stripe rust. Plant and Animal Genome XV, Jan 13-27, 2007, San Diego, CA, pg 117.

Technical Abstract: The Yr5 gene from the Triticum spelta album wheat confers resistance to all races of the wheat stripe rust pathogen (Puccinia striiformis f. sp. tritici) identified so far in the US. To cloneYr5, a sequence tagged site (STS) marker developed from resistance gene analog polymorphism (RGAP) markers cosegregating withYr5 was used to screen a bacterial artificial chromosomal (BAC) library constructed with the Yr5 near-isogenic line in the ‘Avocet S’ background. A sub-BAC clone selected among those from 12 positive BAC clones was sequenced. The 18,244 bp clone contains four coding sequences, one of which was highly homologous to numerous resistance genes and therefore, considered as a candidate gene for Yr5. The candidate gene spans 5,678 bp and contains three exons of 1,563, 720, and 225 bp, two introns of 126 and 1,519 bp, and a 3’-untranslated region of 350 bp. The TATAA promoter region is at the 1,186 bp upstream of the ATG start codon. The 2,508 bp coding sequence encodes a predicted polypeptide of 836 amino acids. The deduced candidate Yr5 protein belongs to the (coiled coil) CC-(nucleotide-binding site) NBS–(leucine rich repeat) LRR class of resistance proteins. The N-terminal region is the CC domain. The NBS domain contains four conserved motifs, kinase 1a (ATP/GTP-binding site motif A, P-loop), kinase 2, kinase 3a, and N-myristoylation site. The LRR domain composed of nine imperfect LRR repeats is at the C-terminal region. Functional analysis of the candidate gene is underway.