جداسازي و معرفي ژن هاي پاسخ دهنده به آلودگي زنگ زرد و قهوه اي در گندم

Isolation and Identification of Genes in Response to Leaf and Stripe Rust Disease in Wheat

Leaf and stripe rusts are major biotic constraints to wheat production throughout the world. The most promising long-term control strategy is to breed and deploy cultivars carrying durable resistance based on minor, slow rusting genes with additive effects. Genes Lr34 and Yrl8 in wheat are tightly linked together and condition adult plant resistance to leaf and stripe rusts, respectively. Differential gene expression analysis was carried out in the near-isogenic lines Thatcher and Thatc\ier-Lr34/Yrl8 following inoculation with leaf rust, using the cDNA-AFLP technique. Fluorescent labelled primers permitted and enabled the identification of polymorphic DNA fragments resolved through PAGE and fluorescence imaging. Over one hundred polymorphic DNA fragments were identified, isolated and cloned. Based on BLASTX and BLASTN results, a majority of polymorphic fragments corresponded to sequences with known metabolic functions. One of the fragments encoding STK-TM-LRR domains is a potential candidate gene for Lr34/Yrl8. This DNA fragment has a high level of similarity to Xa21 in rice, which confers broad-spectrum resistance to diverse strains of Xanthomonas oryzae.