Cloning And Analysis Of Gliadin Genes From Aegilops Tauschii

The Gliadin of wheat ,mostly existing in wheat endosperm, belongs to seed storage proteins. Because Gliadin has intramolecular disulfide bonds, which influence extensibility of dough, the proportion and composing of Gliandin would have great effects on wheat processing quality. A.tauschii ( Aegilops tauschii ( Coes. ) Schmal.DD,2n=14) has a very close evolutional relationship with wheat, which has a similar D genome. Through the research of A.tauschii, lots of positive effects of D genome have been found in decreasing of plant diseases and insect pests in wheat, and it also has the significance in improving the quality and quantity in wheat. At present, many Gliadin genes have been isolated, but there are still a lot of Gliadin which are not researched. That is why we focus on Gliadin research in A.tauschii, and we have already got some results:1) According to characteristic of Gliadin that Gliadin genes have no intron and are conserved in the N-terminal and C- terminal sequences, a pair of degenerate primers(P1/P2) were designed, and 11 Gliadin genes were amplified from the genomes of A.tauschii Rm0182 and Rm0205. After sequencing, we knew that these 11 Gliadin genes are about 850 bp. Furthermore these 11 Gliadin were accessed to Genbank and named:Gliat-1(GQ131527),Gliat-2(GQ131528),Gliat-3(GQ131529),Gliat-4(GQ131530),Gliat-5(GQ131531),Gliat-6(GQ131532),Gliat-7(GQ131533),Gliat-8(GQ131534),Gliat-9(GQ131535),Gliat-10(GQ131536)and Gliat-11(GQ131537)2) By the analysis from Anterpro5.0, seven pseudogenes were identified, which are Gliat-3,Gliat-4,Gliat-5,Gliat-8,Gliat-9,Gliat-10 and Gliat-11. Gliat-1 encoded a mature proteins with 280 amino acid; Gliat-2 encoded a mature proteins with 288 amino acid; Gliat-6 encoded a mature proteins with 288 amino acid; Gliat-7 encoded a mature proteins with 280amino acid. The differences were found mostly in repetitive domain,polygluamine-1 domain and polygluamine-2 domain among four genes. Site-directed mutation,base insertion and deletion is the principal causation of these differences. Through identity of the deduced amino acid sequences, eleven sequences were homologous with the wheat Gliadin. Prediction for secondary structure suggested that low content ofβ-turn existed in Gliat-1,Gliat-6 and Gliat-7, and it may have positive influences on the quality of flour.Conclusively, this experiment not only enriched the genes resource in wheat, but also provided effect in improving quality of wheat in future.