[Cloning and identification of the resistance gene analogs of wheat]

Specific primer sequences were designed on the basis of converse motifs of cloned resistance genes and subsequently used as PCR primers to amplify the resistance gene analog (RGA) in wheat (Triticum aestivum L.) Xinong 88 which possesses rust disease resistance. The amplified products of WRGA1, WRGA2 and WRGA14 were cloned and sequenced. The wheat RGAs contain some conserved motifs such as Kinase-2a, Kinase-3a and HD presenting in known NBS-LRR resistance genes from other plants and share between 46.0%-9.9% amino acid sequence identity with them. The amino acid sequence identity among three RGAs is 80.7%-56.8%. The WRGA1 expression was induced and detected by Northern blotting, which is positively regulated by salicylic acid.