标题：A second \'overexpression\' allele at the Glu-B1 high-molecular-weight glutenin locus of wheat: sequence characterisation and functional effects.
作者：Gao Xin;Appelbee, M. J.;Mekuria, G. T.;Chalmers, K. J.;Mather, D. E.
作者机构：[Gao, X] School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Glen Osmond, SA 5064, Australia, The Key Laborato 更多
通讯作者：Mather, D E
通讯作者地址：[Mather, DE]Univ Adelaide, Waite Res Inst, Sch Agr Food & Wine, Glen Osmond, SA 5064, Australia.
来源：Theoretical and Applied Genetics: International Journal of Breeding Research and Cell Genetics
关键词：alleles;breadmaking;cultivars;cysteine;diet;DNA;effects;flours;gene expression;genes;genetic markers;genetics;gliadin;gluten;glutenins;processing quality;single nucleotide polymorphism;wheat;wheat flour;man;Triticum;Triticum aestivum;Homo;Hominidae;Primates;mammals;vertebrates;Chordata;animals;eukaryotes;Poaceae;Cyperales;monocotyledons;angiosperms;Spermatophyta;plants;Triticum;cultivated varieties;deoxyribonucleic acid
摘要：Bread is one of the major constituents of the human diet and wheat (Triticum aestivum L.) is the most important cereal for bread making. The gluten proteins (glutenins and gliadins) are recognised as important components affecting the processing quality of wheat flour. In this research, we investigated a particular glutenin subunit allele in an Australian cultivar, H45. Based on protein and DNA assays, the Glu-B1 allele of H45 seems to be Glu-B1al, an allele that includes a functional duplication of a gene encoding an x-type high-molecular-weight glutenin subunit, and is thought to increase dough strength through overexpression of that subunit. Yet H45 does not have the dough properties that would be expected if it carries the Glu-B1al allele. After confirming that H45 overexpresses Bx subunits and that it has relatively low un-extractable polymeric protein (an indicator of weak dough), we cloned and sequenced two Bx genes from H45. The sequences of the two genes differ from each other, and they each differ by four single-nucleotide polymorphisms (SNPs) from the sequence that has been reported for the Glu-B1al x-type glutenin genes of the Canadian wheat cultivar Glenlea. One of the SNPs leads to an extra cysteine residue in one of the subunits. The presence of this additional cysteine may explain the dough properties of H45 through effects on cross-linkage within or between glutenin subunits. We propose that the Glu-B1 allele of H45 be designated Glu-B1br, and we present evidence that Glu-B1br is co-inherited with low un-extractable polymeric protein.