| Middle East as the center of genetic diversity of Aegilops tauschii, this study analyzed and identified 80 accessions of the HMW-GS types of Ae. tauschii in the Middle East, further validating the diversity of Ae. tauschii in the Middle East, aiming to find the new subunit type as new resources to improve the genetic diversity of wheat D genome. At the same time through cloning analysis and forecasting new HMW-GS subunit gene, studying gene structure and function of HMW-GS, the relationship between the quality and the application of bread wheat was thrown light upon unequivocally so as to offer theoretical basis of wheat varieties improvement. A contrast was conducted systematically between the gene sequence of Ae. tauschii in the Middle East and the known HMW-GS of wheat and Ae. tauschii, in order to further clarify the origin and evolution relationship of Ae. tauschii. The specific results of the study are as follows:(1) Through the composition analysis of HMW-GS in the Ae. tauschii materials from Middle East, there were 13 kinds of Dx and 14 kinds of Dy subnits, including two new Dx type subunits, according to the mobility, which were named as Dx1.1*t and Dx6*t; also, there were 3 kinds of new Dy type subuits Dy8.2*t, Dy8.2*t and Dy12.5*t, among which, Dx1.1*t and Dx6*t were found as the slowest and fastest xtype subunits currently. In addition, the number of HMW-GS combination types of the materials up to 43, the results revealed that the HMW-GS variant types of Ae. tauschii in the Middle East was very substantial.(2) Through the middle sub cloned way, four HMW-GS gene AY-11-Dx1.5t, AY-11-Dy8.1t, AY-32-Dy12.1t and AY-46-Dy9 t were cloned steadily, the full-length of four gene sequences were 2 541 bp, 1 995 bp, 1 986 bp, 1 986 bp, and its accession number of genebank respectively were KP676569, KP676570, KR054053, KR054054. Statistics the number of β-turn in repeat region of the representative subnits in Glu-1D locus, the results shown that compared with the known representative Dx subunit, the number of β-turn in AY-11-Dx1.5t subunit were 67, and compared with the known Dx more was contained, through predicting it to make the dough had better flexibility; and there was little difference between the Dy subunit in the number of β-turn.(3) HMW-GS subunit gene cloned in this study and the known representative 25 y-types, 33 x-type of HMW-GS gene from NCBI genebank were compared through the gene sequences to build phylogenetic tree respectively. Clustering results of x- type subunit showed that Dx gene of part Ae. tauschii has high homology with common wheat in HMW-GS, it may be involved in the origin and evolution of wheat D genome. Y-type subunit genes were completely together in different genome. The Dy gene divided into three, The AY-11-Dy8.1t and AY-32-Dy12.1t gene cloned in this study gather into the group which were all Dy gene of Ae. tauschii, whereas the gene AY-46-Dy9 t from Iran and some other Dy gene of Ae. tauschii and Dy wheat gene gathered steadily, all of these provided a new theoretical basis for that the D genome of few Ae. tauschii in the Middle East participate in the origin and evolution of HMW-GS of wheat. |
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