冰草高分子量麦谷蛋白亚基基因的分离及结构特征分析  

Isolation and Characterization of High-Molecular-Weight Glutenin Subunit Genes in Agropyron cristatum

作　　者：李少芳[1] 周焕斌[1] 李立会[2] 王献平[1] 张相岐[1] 

机构地区：[1]中国科学院遗传与发育生物学研究所植物细胞与染色体工程国家重点实验室 [2]中国农业科学院作物科学研究所,北京100081

出　　处：《作物学报》2007年第1期63-69,共7页Acta Agronomica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2002CB111300);国家"十五"科技攻关计划项目(2004BA525B03)

摘　　要：通过SDS-PAGE分析,在二倍体、四倍体和六倍体冰草[Agropyron cristatum(L.)Gaertn.]中都检测到2个表达的高分子量麦谷蛋白亚基(HMW-GS),但不同倍性的材料之间,以及相同倍性材料的不同种子之间的HMW-GS组成均有所不同。利用PCR技术对冰草的HMW-GS基因进行克隆,结果从二倍体、四倍体和六倍体冰草中分别克隆了3个、1个和3个y型HMW-GS基因的全长编码区序列。序列分析表明,只有来自六倍体冰草中的Bsy2基因具有完整的开放阅读框,编码1个有487个氨基酸残基、分子量约为53 kD的HMW-GS,大小相当于SDS-PAGE图谱中的大亚基。而其余6个基因均在中间重复区发生了无义突变。本文对冰草HMW-GS基因的结构特点和进化关系进行了分析。Wheat processing quality is closely correlated with composition and quantity of gluten proteins, in particular with high-molecular-weight glutenin subunits （HMW-GS） encoded by the Glu-1 loci （ Glu-A1, Glu-B1 and Glu-D1 ）. In the related species of wheat, there are abundant HMW-GS alleles which are possibly valuable genetic resource for improvement of the wheat processing quality. Agropyron is a closely related genus to wheat and some species in it have been successfully crossed with common wheat and used for variety improvement. However, the HMW-GS in Agropyron was rarely studied. In the present study, SDS-PAGE and PCR methods were used to study the composition and the coding genes of HMW-GS in diploid （PP）, tetraploid （PPPP） and hexaploid （PPPPPP） A. cristatum （L.） Gaertn. The results of SDS-PAGE indicated that the composition of HMW-GS varied not only in different ploidy types （2x, 4x and 6x） but also in different seeds belonging to the same ploidy type since Agropyron cristatum is a cross-pollinated species. There were two expressed HMW- GS totally in each ploidy type. The molecular weigh （MW） of all the subunits in the three types of A. cristatum with different ploidy levels was smaller than that in Chinese Spring. As results of PCR, three y-type HMW-GS genes named as Bty1, Bty2 and Bty3 were isolated from diploid A. cristatum with the length of 1 227 bp, 1 350 bp and 1 530 bp, respectively. One y-type gene named Bfyl was isolated from tetraploid A. cristatum with the length of 1227 bp. And three y-type genes named Bsy1, Bsy2 and Bsy3 were isolated from hexaploid A. cristatum, with the length of 1 227 bp, 1 530 bp and 1 896 bp, respectively. The sequence comparison showed that the homologous relationship of the seven genes was very close. When the ORFs of the seven genes were analyzed, it showed that only Bsy2 in hexaploid A. cristatum possessed an ORF which encoded a protein consisting of 487 amino acid residues with an estimated MW of 53 kD which was similar with the MW of th

关 键 词：冰草 高分子量麦谷蛋白亚基 基因分离 进化 

分 类 号：S543.9[农业科学—作物学]