谷蛋白聚合体大小分布与面粉揉面特性的初步研究

用单向一步SDS-PAGE方法分析表明小麦品种Suneca和Cook在麦谷蛋白5个亚基位点（Glu-B1,Glu-D1,Glu-A3,Glu-B3和Glu-D3)均含不同等位基因。选用Suneca×Cook的F4代群体中麦谷蛋白亚基位点均为纯合基因的60个系,研究麦谷蛋白基因型不同的株系间谷蛋白聚合体粒度大小分布（用SE-HPLC测定）和面粉揉面特性的变异。结果表明,不同的谷蛋白基因型,其谷蛋白聚合体粒度大小相对分布（用不溶谷蛋白聚合体占总谷蛋白聚合体含量的百分数表示,即UPP%）和面团形成时间（即揉面仪曲线图峰值的和面时间,简写PTM）均有显差异;面粉的揉面曲线形状与其UPP%值密切相关;UPP%与PTM呈极显正相关,与揉面仪曲线图峰高（PHM）呈显负相关;与面粉蛋白质含量（FP%）相比,UPP%对PTM和PHM的影响更大些,可作为育种早代品质性状选择一个指标。     

施氮水平对小麦籽粒谷蛋白大聚合体粒径分布的调控效应

谷蛋白大聚合体(GMP)是决定小麦品质形成的重要因素,在小麦籽粒发育过程中,GMP以球形颗粒形式贮藏在小麦籽粒胚乳中,其含量及颗粒大小受亚基组成及环境条件的影响。本研究以不同穗型冬小麦品种为材料,通过大田试验探讨了施氮水平与小麦籽粒谷蛋白大聚合体含量及其颗粒粒径分布的关系。结果表明,在0—240kg?hm-2范围内增施氮肥能显著提高小麦籽粒中GMP的含量,施氮量继续增加则不利于小麦籽粒 GMP积累。小麦籽粒GMP颗粒粒径分布范围为0.375—256 μm;GMP颗粒的体积和表面积分布均呈双峰曲线,数目分布呈单峰曲线。在0—240kg?hm-2范围内增施氮肥能显著提高>10μmGMP颗粒数目百分比和体积百分比,表明施氮能促进大颗粒GMP的形成。不同品种对施用氮肥的反应呈现差异。大穗型品种泰山9818籽粒GMP含量及颗粒粒径分布对氮肥的反应较为敏感。     

不同灌水处理对强筋小麦谷蛋白大聚合体粒度分布和品质的影响

在田间条件下,以两个优质强筋小麦品种(藁城8901和济麦20)为供试材料,研究了不同灌水处理(全生育期不灌水、拔节期灌1次水、越冬期和拔节期灌2次水、越冬期、拔节期和灌浆期灌3次水,每次灌水量675 m³·hm^-2)对强筋小麦谷蛋白大聚合体含量与粒度分布、品质和产量的影响.结果表明: 两个小麦品种的面团形成时间、面团稳定时间、面包体积、籽粒产量、谷蛋白大聚合体含量以及体积加权平均粒径、表面积加权平均粒径、粒径>100 μm的体积百分比和表面积百分比均以灌2水处理最高.相关分析显示,两个小麦品种的面团形成时间、面团稳定时间和面包体积与粒径<10 μm和10～100 μm的谷蛋白大聚合体颗粒体积百分比呈显著负相关,而与粒径>100 μm的谷蛋白大聚合体颗粒体积百分比、体积加权平均粒径和表面积加权平均粒径呈显著正相关.水分供应过多或过少均不利于籽粒产量和品质的同步改善,灌溉水平可通过改变谷蛋白大聚合体粒度分布影响小麦籽粒品质.     

基因枪法转化小麦谷蛋白基因研究进展

小麦面粉品质的优劣主要取决于麦谷蛋白多聚体结构的组成,谷蛋白多聚体由高分子量谷蛋白亚基(HMW-GS)、低分子量谷蛋白亚基(LMW-GS)和醇溶蛋白以二硫键相互交联构成,其数量和结构特征直接影响面团的粘弹性,所以通过基因工程方法转化优质谷蛋白基因,增加谷蛋白数量,改善谷蛋白多聚体结构组成,进而改良面粉品质的研究逐渐引起国内外的重视,并在近年来取得了重要进展。基因枪法是目前利用基因工程改良小麦品质的主要途径,自1992年以来已在多个研究室取得了较为瞩目的成果,显示了基因工程改良小麦品质的可能性及前景。综述了迄今为止国内外利用基因枪法转化谷蛋白基因改良小麦品质的研究进展,并在受体材料的选择等方面的研究现状作了较为详细的阐述。     

小麦低分子量麦谷蛋白亚基组成研究

利用改良的两步一向SDS—PAGE(two—step one—dimensional SDS—PAGE)分析了几种小麦低分子量麦谷蛋白亚基(LMW-GS)组成。70％热乙醇提取总谷蛋白,11％分离胶进行第一步SDS—PAGE分离．电泳1h后切取顶端1cm胶条并置于巯基乙醇溶液进行还原,还原后的胶条于11%～16．5％的梯度胶进行第二步SDS—PAGE分离。结果显示。两步一向SDS—PAGE可以彻底除去清蛋白、球蛋白和醇溶蛋白对LMW—GS分离的背景干扰。提高LMW—GS的分辨率。对几种小麦低分子量麦谷蛋白亚基分析表明：LMW-GS组合比HMW—GS更为丰富,每种小麦含有2～5种B亚基,2～4种C亚基．B、C亚基的总数量为4～8种。     

灌浆期不同阶段遮光对小麦籽粒蛋白质组分含量和加工品质的影响

选用强筋小麦济麦20、中筋小麦泰山23和弱筋小麦宁麦9号3个小麦品种,设置了灌浆期不同阶段遮光处理:开花后不遮光(S0)、0～11 d遮光(S1)、12 ～23 d遮光(S2)、24～35 d遮光(S3),研究了其对不同小麦品种籽粒蛋白质组分含量和加工品质的影响.结果表明:3个小麦品种的籽粒清蛋白+球蛋白含量遮光处理间无显著差异;遮光均显著提高了济麦20和泰山23的高分子量谷蛋白亚基、低分子量谷蛋白亚基、谷蛋白、醇溶蛋白和总蛋白含量,其中灌浆中期遮光(S2)处理提高幅度高于其他处理;灌浆中期(S2)和后期(S3)遮光处理显著提高了宁麦9号各蛋白质组分含量.遮光显著降低了小麦籽粒产量,提高了籽粒面团形成时间、面团稳定时间和沉降值,其中灌浆中期遮光处理更为显著,表明籽粒品质的形成与灌浆中期的光照条件更为密切.总体上灌浆期遮光对3个小麦品种籽粒产量、蛋白质组分含量及加工品质指标的调节幅度为济麦20＞泰山23＞宁麦9号.     

小麦高分子量麦谷蛋白亚基鉴定及其品质效应研究进展

高分子量谷蛋白亚基(HMW-GS,high molecular weight glutenin subunits)是小麦子粒贮藏蛋白的重要组成成分,其组成、搭配、表达水平及含量决定面团弹性和面包加工品质。本文主要介绍了小麦HMW-GS编码基因的克隆、分子特征、分子标记开发及其在小麦育种中的应用,并综述了不同HMW-GS与面粉加工品质之间的关系,以及HMW-GS基因遗传转化、微量配粉和突变体培育等方面的研究进展,分析了目前研究中存在的主要问题,认为通过分子标记辅助选择和转基因技术聚合优质亚基,培育优质面包小麦品种和明确各个HMW-GS基因的品质效应是今后的研究重点。     

小麦HMW-GS基因及其AS-PCR分子标记研究进展

小麦高分子量谷蛋白亚基(HMW-GS)与小麦品质性状,尤其是沉降值性状显著相关。利用其做分子标记选育聚合优质亚基的品种,具有快速、简单、实用、有效的特点。目前,普通小麦基因组中已有15个已命名Glu-1基因被克隆和测序,这使设计引物序列、进行等位基因的特异性扩增成为可能。对普通小麦高分子量谷蛋白亚基基因组成特点及分子标记现状进行了分析,并针对国内利用高分子量谷蛋白亚基进行分子标记辅助育种做了展望。     

小麦高分子量谷蛋白亚基效应的比较研究

采用SDS-PAGE方法,通过对5个亲本间杂交获得的F2群体每一单株的F3籽粒样本及其亲本进行小麦高分子量谷蛋白亚基（HMW-GS）组成分析,并对每一F2单株上F3籽粒群体的高分子量谷蛋白亚基组成与其籽粒蛋白质含量、SDS-沉降值的关系进行研究,分析比较黄淮麦区出现频率较高的7个亚基或亚基对的品质效应。结果表明：小麦高分子量谷蛋白亚基组成不同群体间籽粒的蛋白质含量和SDS-沉降值基本达到显著或极显著水平。优质亚基表现为：1、7＋8、14＋15和5＋10亚基。因此,黄淮麦区小麦育种应加强对这些优质亚基的引入和利用,特别是对14＋15和5＋10亚基的引入和利用。     

水稻57H突变体系列的胚乳储藏蛋白质表型多样性及其分类(英文)

种子储藏蛋白质主要由谷蛋白、醇溶谷蛋白和球蛋白组成。这些蛋白质在种子发育期被合成后,经过区室化过程,被蓄积在胚乳中。本研究系统分析了水稻57H突变体的表型多样性,旨在为胚乳储藏蛋白质的遗传调节机制的全面解明展示一个新的前景。胚乳蛋白质的SDS-PAGE分析和免疫印迹分析显示了高量含有57kD谷蛋白前体的水稻57H突变体系列具有多样的储藏蛋白质表型。基于其表型的多样性,57H突变体系列被分成了三种类型。与野生型水稻品种相比,所有的类型Ⅰ突变体(glup4,glup6,Glup5,esp2)不仅高量蓄积谷蛋白前体、少量蓄积成熟型谷蛋白的40kD酸性亚基和20kD碱性亚基,而且显著减少了13kD醇溶谷蛋白b组分和26kDa球蛋白的蓄积;类型Ⅱ突变体(Glup1,glup2)不仅高量蓄积谷蛋白前体,还减少了26kDa球蛋白的蓄积;类型Ⅲ突变体(glup3)除了高量蓄积谷蛋白前体、少量蓄积成熟型谷蛋白亚基之外,并没有减少其它储藏蛋白质的蓄积。结果指出了57H变异系列对储藏蛋白的蓄积具有多样的影响,实质上是关于储藏蛋白质区室化的遗传体系。并就该遗传体系对储藏蛋白质的翻译后区室化及其营养性状的可能的影响进行了讨论。     

小麦HMW-G12亚基基因启动子克隆及序列分析

为了研究高分子量谷蛋白基因启动子在种子中的特异性表达,以小麦品种“东农7742”的基因组DNA为模板,根据已发表序列设计并合成引物,用PCR的方法克隆了小麦贮藏蛋白中高分子量谷蛋白12亚基基因的上游调控序列。序列测定结果表明：所克隆的启动子片段大小为424bp与Thomspon报道的序列比较,同源性为97.9%,有9个核苷酸发生了改变。推测的TATA box位于-27— -30bp,Prolamin-box位于-175— -181bp,认为该元件可能与转录速率的调控有关。     

Chromosomal control of glutenin subunits in aneuploid lines of wheat: analysis by reversed-phase high-performance liquid chromatography

Summary Glutenin subunits from nullisomic-tetrasomic and ditelocentric lines of the hexaploid wheat variety ‘Chinese Spring’ (CS) and from substitution lines of the durum wheat variety ‘Langdon’ were fractionated by reversed-phase high-performance liquid chromatography (RP-HPLC) at 70 °C using a gradient of acetonitrile in the presence of 0.1% trifluoroacetic acid. Nineteen subunits were detected in CS. The presence and amounts of four early-eluted subunits were found, through aneuploid analysis, to be controlled by the long arms of chromosomes 1D (1DL) (peaks 1–2) and 1B (1BL) (peaks 3–4). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that these four subunits are the high molecular weight subunits of glutenin, which elute in the order 1Dy, 1Dx, 1By, and 1Bx. Similar amounts of 1DL subunits were present (6.3 and 8.8% of total glutenin), but 1BL subunits differed more in abundance (5.4 and 9.5%, respectively). Results indicate that most late-eluting CS glutenin subunits were coded by structural genes on the short arms of homoeologous group 1 chromosomes: 6 by 1DS, 5 by 1AS, and 4 by 1BS. Glutenin of tetraploid ‘Langdon’ durum wheat separated into nine major subunits: 6 were coded by genes on 1B chromosomes, and 3 on 1A chromosomes. Gene locations for glutenin subunits in the tetraploid durum varieties ‘Edmore’ and ‘Kharkovskaya-5’ are also given. These results should make RP-HPLC a powerful tool for qualitative and quantitative genetic studies of wheat glutenin. The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned Stationed at the Northern Regional Research Center, Peoria.     

湖北推广小麦品种(系)高分子量麦谷蛋白亚基组成分析

应用SDS-PAGE技术分析了45份湖北推广小麦品种(系)籽粒的高分子量麦谷蛋白亚基组成。40份材料的高分子量麦谷蛋白亚基组成为同质,5份为异质。在Glu-1位点共检测到9种等位基因变异类型,其中Glu-A1位点有“1、2^ 、Null”3种变异类型,Glu-B1位点有“7、7 8、7 9、14 15”4种,Glu-D1位点有“2 12、5 10”2种。“Null、7 8、2 12”是主要亚基,它们的频率分别是62．5％、60％和72．5％。亚基组合类型有12种,其中(Null,7 8,2 12)亚基组合占30．0％,(1,7 8,2 12)、(1,14 15,2 12)、(Null,7 9,2 12)、(Null,7 8,5 10)4种组合的频率都在10％以上,这5种亚基组合占总组合的72．5％。供试小麦材料品质评分在5～10之间,平均评分为7．0。含5 10亚基的品种(系)所占比例低,是湖北小麦烘烤品质较差的部分原因。     

Identification of a transposon-like insertion in a Glu-1 allele of wheat

Summary The Glu-1 locus, present on the long arms of the group 1 chromosomes of wheat, codes for a group of storage protein polypeptides termed high molecular weight (HMW) subunits of glutenin. Hexaploid wheat varieties carry a silent Glu-1y allele on chromosome 1A, no polypeptide being attributable to this locus. When two such alleles from different varieties were compared, one was found to contain an 8 kb insertion of DNA, termed Wis-2, interrupting the coding sequence. The insertion site is flanked by a 5 bp duplication. The two ends of Wis-2 contain similar sequences over 500 bp long and its termini contain almost the same short sequences but in opposite orientation. These terminal sequences are related to those of several retroposon-type transposable elements found in other organisms.     

Identification of new low-molecular-weight glutenin subunit genes in wheat

To clarify the composition of low-molecular-weight glutenin subunits (LMW-GSs) in a soft wheat cultivar, we cloned and characterized LMW-GS genes from a cDNA library and genomic DNA in Norin 61. Based on alignment of the conserved N- and C- terminal domains of the deduced amino-acid sequences, these genes are classified into 12 groups. One of these groups (group 5), the corresponding gene of which has not been reported previously, contains two additional hydrophobic amino-acid clusters interrupting the N-terminal repetitive domain. Other groups (groups 11 and 12), which were not identified in other cultivars as a protein product, showed all eight cysteines in the C-terminal conserved domain. With specific primer sets for these groups it was revealed that Glu-D3 and Glu-A3 encoded the former and the latter, respectively. Both groups of genes were expressed in immature seeds. The presence of these groups of LMW-GSs may affect the dough strength of soft wheat. Received: 26 March 2001 / Accepted: 16 July 2001     

Cloning and Expression of Low Molecular Weight Glutenin Genes from the Chinese Elite Wheat Cultivar ＂Xiaoyan 54＂

The low molecular weight （LMW） glutenln subunlts account for 40% of wheat gluten protein content by mass and these proteins are considered to significantly affect dough quality characteristics. Five new full-length LMW glutenln genes （designated LMW-5, LMW-7, LMW-42, LMW-58, and LMW-34） were isolated from the Chinese elite wheat cultivar ＂Xlaoyan 54＂ by PCR amplification of genomlc DNA using a pair of degenerate primers designed from the conserved sequences of the N- and C-terminal regions of published LMW glutenln genes. Deduced amino acid sequence analysis showed that LMW-5 belongs to the LMW-i type genes and that the other four belong to LMW-m type genes. Sequence comparisons revealed that point mutations occasionally occurred in signal peptide and N-terminus domains and often existed in domain III and domain V. Small insertions and deletions are represented in the repetitive domain. There is a stop codon after amino acid position 110 In the repetitive domain of LMW.34, indicating that It is a pseudogene. The other four genes have complete open reading frames and the putative mature regions of these genes were subcloned Into pET-30a expression vector and successfully expressed in Escherlchla coll. Protein sodium dodecyl sulfate-polyacrylamlde gel electro- phoresls analysis showed that all proteins expressed in E. coil by the four genes could be related to B-group LMW glutenln subunits of wheat.     

Molecular characterization of a low-molecular-weight glutenin cDNA clone from Triticum durum

Summary A full-length, low-molecular-weight (LMW) glutenin cDNA clone, pTdUCD1, has been isolated from a Triticum durum cv Mexicali wheat cDNA library. The complete sequence was determined and compared to the LMW glutenin genes that have been isolated from hexaploid wheat, Triticum aestivum. This cDNA codes for a protein of 295 amino acids (33,414 daltons) including a 20-amino acid signal peptide as deduced from the DNA sequence. Northern analysis showed that this cDNA hybridizes to a family of related sequences ranging in length from 1,200 to 1,000 nucleotides. This gene is similar but not identical to previously published LMW glutenin gene sequences. The most striking characteristic of all cloned LMW glutenin genes is the conservation of eight cysteine residues, which could be involved in potential secondary or tertiary structure, disulfide bond interactions. This paper presents a structural map defining distinct regions of the LMW glutenin gene family.     

小麦新品种(系)Glu-1位点等位基因变异研究

应用SDS-PAGE技术分析了40份小麦新品种(系)的高分子量麦谷蛋白亚基等位基因变异。在Glu-1位点共检测到10种变异类型,其中Glu-Al位点有3种类型：Null、1、26 ,Glu-B1位点有5种类型：7 8、7 9、14 15、7、17 18,Glu-D1位点有2种类型：2 12、5 10;Null(54．3％)、7 8(51．4％)和2 12(62．9％)分别是Glu-Al、Glu-B1和Glu-D1位点上的主要亚基变异类型。另外,在2份材料的Glu-B1和Glu-D1位点各检测到1个新的亚基,分别命名为1By8．1和1Dx5^ 。Glu-1位点的Nei‘s遗传变异指数平均为0,5648,Glu-B1的遗传多样性最高,Glu-D1最低。供试小麦材料Glu-1位点的HMW-GS组合共有17种类型,以(Null,7 8,2 12)组合为主要类型,占31．4％;有9种亚基组合类型分别只在1份材料中出现,占26.1％。结果表明,这些小麦新品种(系)存在着丰富的亚基组合类型。