3个新疆地方小麦品种Glu-A3位点低分子量谷蛋白亚基新基因的序列分析

The Analysis of Low Molecular Weight Glutenin Subunit Gene Sequences Coding by Glu-A3 Locus in 3 Xinjiang Wheat Landraces

麦谷蛋白可分为高分子量麦谷蛋白亚基(HMW-GS)和低分子量麦谷蛋白亚基(LMW-GS),其中低分子量麦谷蛋白亚基对小麦品质具有重要影响。本文采用PCR方法从中国小麦微核心种质中的3个新疆小麦品种红春麦(新疆玛纳斯)、红春麦(新疆昌吉)和红金包银(新疆伊吾)中分别得到了3个低分子量麦谷蛋白亚基(LMW-GS)新基因(GenBank:DQ519084、DQ519085和DQ517534)。它们具有LMW-i型基因的典型结构特征,与已报道的Glu-A3位点编码的LMW-GS基因序列有很高的一致性,高达79.06%～94.24%。DQ519084和DQ517534在C末端保守区有9个半胱氨酸残基,DQ519085其编码区内存在1个提前终止密码子,推测其为假基因。

Gluteinins are multimeric aggregates of high molecular weight glutenin subunit （HMW-GS） and low molecular weight glutenin subunit （LMW-GS）, which determined the quality in wheat. Using PCR-amplification method, three new LMW-GS genes （GenBank： DQ519084, DQ519085 and DQ517534） were isolated from genomic DNA of 3 Xinjiang wheat landraces （Hongchunmai from Xinjiang Changji, Hongchunmai from Xinjiang Manasi and Hongjinbaoyin from Xinjiang Yiwu）, which were parts of Chinese wheat mini-core collections. Nucleotide sequence comparison of them with other reported LMW-GS genes located at Glu-A3 loci showed the degree of identity among them ranged from 79.06% to 94.24%. The deduced amino acid sequences showed that they were typical LMW-i genes. The deduced sequence of DQ519084 and DQ517534 both contained 9 cysteine residues, one more cysteine residue in the C-terminal conserved domain than the typical LMW-GS genes. DQ519085 contained a stop code in its coding region, so it is presumed as a pseudogene.