高冰草中一种新型高分子量麦谷蛋白亚基编码序列的研究

Study on a novel HMW glutenin subunit coding region from Agropyron elongatum

高冰草 Agropyronelongatun 是普通小麦 Triticumaestivum 的近缘禾草,SDS-PAGE显示其所编码的麦谷蛋白亚基的类型较普通小麦更加丰富,是普通小麦品质改良的重要亲本之一.利用基因组PCR的方法从高冰草中克隆到一个新的高分子量麦谷蛋白亚基 HMW-GS 基因 AgeloG2 全编码序列,同源性分析表明:与普通小麦的1Dy12基因比较在少数位点发生了碱基替换和一处6碱基序列的缺失,同源性为99%;与普通小麦的1Dy10基因比较,该基因亦只有少数碱基的替换和两处18碱基序列的增加及一处6碱基序列的缺失,同源性为98%.从推导的编码序列分析,AgeloG2编码y型HMW-GS.综上分析,AgeloG2是一个新的高分子量麦谷蛋白y-型亚基基因.聚类分析结果显示,无论在基因序列还是推导的氨基酸序列上,小麦1Dy亚基与AgeloG2的同源性都高于与粗山羊来源的y型亚基的同源性.

Agropyron elongatum is a near-related species of common wheat. SDS-PAGE indicated that the composition of glutenin subunits in Agropyron elongatum was much more abundant than that in common wheat. A novel high molecular weight glutenin subunit (HMW-GS) gene AgeloG2 coding sequence of Agropyron elongatum was isolated using genomic PCR analysis. The DNA sequence was compared with those of homologous of common wheat. The results show that there are only a few bases substitutions and one motif (of 6 bases) deletion based on 1Dy12, so the homologous of AgeloG2 and 1Dy12 are 99%. Also, there are a few base substitutions, one motif (of 6 bases) deletion and two motifs (of total 18 bases) addition based on 1Dy10, so the homologous of AgeloG2 and 1Dy10 are 98%. The deduced amino acid sequence from the coding sequence indicates that AgeloG2 is a new y-subunit gene of HMW-GS. Cluster analysis of y-subunit genes from wheat, Aegilops tauschii (DD) and this new one, as well as derived amino acid sequences from them show that the homologous of the new gene with wheat is higher than Ae. Tauschii (97%).