Characterization of low-molecular-weight glutenin genes in Aegilops tauschii
Characterization of low-molecular-weight glutenin genes in Aegilops tauschii
复制标题
DOI：
10.1007/s00122-004-1711-z
复制
发表时间：
2004-09-01
影响因子：
5.4
通讯作者：
Gale, KR
中科院分区：
文献类型：
--
作者：
Johal, J;Gianibelli, MC;Gale, KR
本文报道了节节山羊草（同义词小麦）的低分子量（LMW）麦谷蛋白基因家族的特征，节节麦是六倍体小麦的 D 基因组供体。通过分析与 LMW 麦谷蛋白探针杂交呈阳性的细菌人工染色体 (BAC) 克隆，鉴定出七个独特的 LMW 麦谷蛋白基因。对这些基因进行了测序，包括其非翻译的 3' 和 5' 侧翼区域。推导的基因氨基酸序列揭示了四个假定的活性基因和三个假基因。所有这些基因与六倍体小麦中的 LMW 麦谷蛋白具有非常高的相似性。成熟蛋白质的预测分子量在32.2 kDa至39.6 kDa之间，蛋白质的预测等电点在7.53至8.06之间。所有推导的蛋白质均为LMW-m 型。七个 LMW 麦谷蛋白基因的组织似乎散布在至少数百个碱基对上，每个 BAC 克隆仅存在一个基因或假基因就表明了这一点。 Ae 基因组 DNA 的 Southern 印迹分析。节节豆和含有七个 LMW 麦谷蛋白基因的 BAC 克隆表明，BAC 克隆含有基因组中存在的所有 LMW 麦谷蛋白杂交带。来自伊蚊的 LMW 麦谷蛋白提取物的二维凝胶电泳。对节节线进行了检测，结果显示至少存在 11 种不同的蛋白质。进一步分析表明，一些观察到的蛋白质是修饰的麦醇溶蛋白。这些结果表明，典型的 LMW 麦谷蛋白的实际数量实际上可能比之前想象的要低得多，并且聚合物部分中还存在许多修饰的麦醇溶蛋白。
This paper reports the characterization of the low-molecular-weight (LMW) glutenin gene family of Aegilops tauschii (syn. Triticum tauschii), the D-genome donor of hexaploid wheat. By analysis of bacterial artificial chromosome (BAC) clones positive for hybridization with an LMW glutenin probe, seven unique LMW glutenin genes were identified. These genes were sequenced, including their untranslated 3' and 5' flanking regions. The deduced amino acid sequences of the genes revealed four putative active genes and three pseudogenes. All these genes had a very high level of similarity to LMW glutenins characterized in hexaploid wheat. The predicted molecular weights of the mature proteins were between 32.2 kDa and 39.6 kDa, and the predicted isoelectric points of the proteins were between 7.53 and 8.06. All the deduced proteins were of the LMW-m type. The organization of the seven LMW glutenin genes appears to be interspersed over at least several hundred kilo base pairs, as indicated by the presence of only one gene or pseudogene per BAC clone. Southern blot analysis of genomic DNA of Ae. tauschii and the BAC clones containing the seven LMW glutenin genes indicated that the BAC clones contained all LMW glutenin-hybridizing bands present in the genome. Two-dimensional gel electrophoresis of an LMW glutenin extract from Ae. tauschii was conducted and showed the presence of at least 11 distinct proteins. Further analysis indicated that some of the observed proteins were modified gliadins. These results suggest that the actual number of typical LMW glutenins may in fact be much lower than previously thought, with a number of modified gliadins also being present in the polymeric fraction.