Browsing by Subject "Stem Rust Resistance"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Barley stem rust resistance genes: structure and function(Plant Genome, 2009-07) Steffenson, Brian; Kleinhofs, Andris; Brueggeman, Robert; Nirmala, Jayaveeramuthu; Zhang, Ling; Mirlohi, Aghafakhr; Druka, Arnis; Rostoks, NilsRusts are biotrophic pathogens that attack many plant species but are particularly destructive on cereal crops. The stem rusts (caused by Puccinia graminis) have historically caused severe crop losses and continue to threaten production today. Barley (Hordeum vulgare L.) breeders have controlled major stem rust epidemics since the 1940s with a single durable resistance gene Rpg1. As new epidemics have threatened, additional resistance genes were identified to counter new rust races, such as the rpg4/Rpg5 complex locus against races QCCJ and TTKSK. To understand how these genes work, we initiated research to clone and characterize them. The Rpg1 gene encodes a unique protein kinase with dual kinase domains, an active kinase, and a pseudokinase. Function of both domains is essential to confer resistance. The rpg4 and Rpg5 genes are closely linked and function coordinately to confer resistance to several wheat (Triticum aestivum L.) stem rust races, including the race TTKSK (also called Ug99) that threatens the world's barley and wheat crops. The Rpg5 gene encodes typical resistance gene domains NBS, LRR, and protein kinase but is unique in that all three domains reside in a single gene, a previously unknown structure among plant disease resistance genes. The rpg4 gene encodes an actin depolymerizing factor that functions in cytoskeleton rearrangement.Item Linkage between the Rpg1 gene for stem rust resistance and the f5 locus on barley chromosome(Crop Science, 1993) Steffenson, Brian; Jin, Yue; Franckowiak, Jerome DLinkage studies can expedite the transfer of agronomically important genes in breeding programs. A study was conducted to determine the linkage relationship between loci segregating for stem rust (Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn.) resistance (Rpg1) and a chlorina mutant (f5), and to confirm the linkage among Rpg1, br1 (brachytic) and fc (chlorina seedling). ‘Bowman’ barley (Hordeum vulgare L.) was crossed to genetic stocks possessing br1, fc, and f5, respectively. Estimates of linkage distances were 9.6 ± 1.4% between Rpg1 and br1, 13.6 ± 1.8% between Rpg1 and fc, and 25.9 ± 2.6% between Rpg1 and f5. The linkage between Rpg1 and f5 was established.