Identification and expression pattern of PtGSP1 protein in wheat leaf rust using YST system

Plant pathogens secret their effector proteins into host cell in order to suppress plant defense system. Knowing precise molecular aspect of this invasion helps for the development of novel desease control strategies. Using yeast secretion system, a wheat leaf rust cDNA library was cloned upstream of invertase coding ORF in an expression vector and sent to the mutant yeast which is deficient for invertase production. CDNA cloneds containg signal peptid were able to secret recombinant invertase outside of the host cell and provided glucose for their growth. Using this sytem, a novel gene here we named ptGSP1, was isolated, and its expression was confirmed in the germinated and haustorial stages of the rust life sycle. Also, fast evolution of PtGSP1 coding region was deduced from comparing sequences of this gene in the geographical starins. Its secertion nature, size of the deduced protein, fast evolution of the ORF and its expression at huastorial intimate stage, all emphesis on its possible role during the pathogenesis.