不同品质类型小麦谷蛋白聚合体含量及亚基组成的初步研究

以6个不同品质类型小麦品种为试验材料,对其面粉总蛋白含量(FP％)、谷蛋白总聚合体含量(TGP％)、大聚合体含量(GMP％)进行了测定和比较,并利用多层浓缩胶SDS—PAGE对不同品种小麦面粉大聚合体亚基组成进行了初步分析。结果表明：(1)面包和面条型小麦面粉谷蛋白总聚体含量明显高于饼干型小麦;(2)分子量约为32—43kD和14kD的亚基主要是组成麦谷蛋白大聚合体。     

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。     

西北春麦区小麦地方品种高分子量麦谷蛋白亚基组成分析

为了给品质改良提供基础材料,并了解西北春麦区小麦地方品种的遗传多样性,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)方法,分析了493份小麦地方品种的高分子量麦谷蛋白亚基(HMW-GS)的组成.结果表明:在供试材料中,Glu-1位点共有26个等位基因,其中Glu-A1位点3个,Glu-B1位点9个,Glu-D1位点14个,亚基null、7+8、2+12在各自的位点上出现频率最高,分别达到了94.53%、92.92%、86.24%;亚基组成类型共有30种,主要为null/7+8/2+12,频率达79.76%;同时筛选出一些含有1、2*、13+16、14+15、5+10、1.5+10等优质亚基或亚基对的材料,可作为优质基因源;西北春麦区小麦地方品种间Glu-1位点的遗传多样性,以Glu-D1位点最高,其次是Glu-B1位点,Glu-A1位点最低.     

小麦低分子量麦谷蛋白亚基功能标记研究进展

小麦是我国主要的粮食作物之一,籽粒中的低分子量麦谷蛋白对于小麦面包的加工品质具有重要的作用。近年来,利用分子标记技术检测小麦低分子量麦谷蛋白亚基（low molecular weight glutenin subunit,LMW-GS）的类型和组成已成为小麦品质改良的研究热点之一。主要综述了小麦低分子量麦谷蛋白亚基基因和蛋白质的结构特征、分类以及功能标记的研究进展,讨论了开发利用小麦Glu-A3、Glu-B3、Glu-D3位点LMW-GS功能标记的意义及存在的问题,并强调了LMW-GS分子标记检测技术的革新及亚基类型的完善对小麦品质改良的重要性,以期加速LMW-GS功能标记在优质小麦育种工作中的应用进程。     

西南冬麦区地方品种HMW-GS组成遗传多样性研究

采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)对西南冬麦区(云南、贵州、四川)3个省份共计560份小麦地方品种的高分子量谷蛋白亚基(HMW-GS)组成进行了研究。结果表明:Glu-1位点共有22种等位基因,其中Glu-A1位点4种、Glu-B1位点11种、Glu-D1位点7种;亚基null、7 8和2 12在各自位点的频率最高,分别为89.64%、68.21%和96.43%。亚基组成类型共有46种,以null/7 8/2 12和null/7 9/2 12为主,频率分别为50.89%和11.79%。在这些材料中筛选出一些含有1、2*、17 18、14 15、5 10等优质亚基的材料,其中有52份材料含有优质亚基组合。     

67份美国小麦种质资源的HMW-GS组成与品质分析

为了挖掘新的种质资源,对引自美国的67份小麦种质材料进行了高分子量麦谷蛋白亚基组成与品质性状分析。HMW-GS组成分析表明,在供试材料中共检测到20种亚基类型和25种亚基组合,表明这批材料的遗传多样性较高。在GluA1位点上,亚基1与2*的出现频率分别为16.4%与35.8%;Glu-B1位点有9个等位变异,其中出现频率最高的为7+9亚基对(47.8%);Glu-D1位点有8个等位变异,以5+10亚基对为主要类型,出现频率高达74.6%。在Glu-B1位点上发现3个不常见亚基7*、8*、8**和3个未知亚基a、b、c,还发现1个未知亚基,暂时将其标记为5*,可能位于Glu-D1位点上。亚基组合类型中,"null,7+8,5+10"的出现频率最高,为22.4%。亚基评分在5~10分之间,平均8.2分,得分在8分及其以上的材料有42份(62.69%),其中得10分的材料有9份(13.43%)。利用DA7200近红外成分分析仪对这批小麦材料的品质性状进行初步分析,结果表明其品质指标较低。这67份美国小麦材料含有的优质亚基比例较高,可作为中间材料以改良我国黄淮麦区小麦品种的亚基组成。     

陕南鄂西丘陵麦区小麦HMW-GS组成和LMW-GS等位基因变异

采用SDS-PAGE凝胶电泳和STS标记方法分别对陕南鄂西丘陵麦区小麦品种(系)中的高分子量谷蛋白亚基(HMW-GS)组成和低分子量谷蛋白亚基(LMW-GS)Glu-A3与Glu-B3位点的等位基因进行了检测,并通过STS特异性标记对SDS-PAGE凝胶电泳检测的HMW-GS部分结果进行了验证。结果表明:(1)陕南麦区64份小麦材料中共检测到9种HMW-GS类型,其中Glu-A1位点含有Null、1共2种等位变异,频率分别为53.12%和46.88%;Glu-B1位点有7+8、7+9、14+15和17+18共4个等位变异,频率分别为26.56%、48.44%、21.88%和3.13%;Glu-D1位点有2+12、5+10和4+12共3种等位变异,频率为71.88%、15.63%和12.49%;而且17种不同亚基组合中以"1,7+9,2+12"与"Null,7+9,2+12"为主。(2)64份小麦材料中检测到11种LMW-GS类型,其中Glu-A3位点存在Glu-A3a、Glu-A3c和Glu-A3d共3种等位变异,分布频率为10.94%、62.50%和26.56%;GluB3位点有Glu-B3a、Glu-B3b、Glu-B3d、Glu-B3e、Glu-B3f、Glu-B3g、Glu-B3i和Glu-B3j共8种等位变异,分布频率分别为6.25%、4.69%、29.69%、1.56%、3.13%、18.75%、4.69%、31.25%。(3)2个特异性STS标记对SDSPAGE凝胶电泳检测到的HMW-GS部分组成结果验证表明,STS标记可以有效克服SDS-PAGE方法检测小麦HMW-GS中的7与7*、8与8*以及2与2*亚基的误读问题,为小麦品质育种与食品加工提供理论支持。     

小偃6号及其衍生后代品质相关性状基因的分子检测

小偃6号是我国小麦育种的重要骨干亲本之一。本研究利用UMN19、UMN25、UMN26、T2、T5、T13、S13、S1、T1、Wx-A1、Wx-B1、Wx-D1、YP7A、YP7B-1、PPO18、PPO29等16个功能型分子标记对小偃6号及其衍生后代的品质相关性状的基因组成进行了检测和分析。结果表明:在高分子量谷蛋白亚基两位点(Glu-A1、Glu-D1)和Waxy蛋白基因位点上,分别有78.72%、82.98%的衍生品种与骨干亲本小偃6号等位基因一致,但少数品种具有不同的优良亚基等位基因Ax2*或Dx5+Dy10;在低分子量谷蛋白亚基两位点(Glu-B3、Glu-D3)上,有25.33%的衍生品种与小偃6号等位基因一致;在八氢番茄红素合成酶基因位点Psy-A1、Psy-B1和多酚氧化酶(PPO)活性等位基因位点上,仅有17.02%和38.29%的衍生品种与小偃6号一致;并探讨了不同品质相关性状基因位点在衍生后代传递频率存在差异的原因。     

山西小麦育成品种品质性状及HMW-GS组成演变分析

研究山西省小麦育成品种的品质及高分子量麦谷蛋白亚基的演变,有助于优异种质资源的挖掘和创新,可以为小麦品质改良和品种推广提供依据。对山西小麦育成品种的品质及HMW-GS组成进行演变分析,结果表明,山西小麦整体上以中筋为主,除硬度指数呈逐年下降趋势外,其他品质指标在20世纪90年代之前均逐渐提升,而后呈现下降趋势;山西省小麦品种HMW-GS的Glu-1位点等位变异较为丰富,Glu-A1位点有1、2*和Null 3种亚基类型,Glu-B1位点有7种亚基类型(7+8、7+9、6+8、13+16、14+15、17+18、20),Glu-D1位点有6种亚基类型(2+12、2+10、5+12、5+10、4+12和2. 2+12),共检测到亚基组合类型32种,"Null,7+8,2+12"出现频率最高,且优质亚基的变化与品质演变趋势一致; Glu-D1位点对蛋白质含量、硬度指数、容重、湿面筋含量、延伸性和吸水率的效应较大,其中4+12和2+10对蛋白质含量和湿面筋含量具有正效应,Glu-B1位点主要影响沉降值、形成时间、稳定时间、拉伸面积和最大抗延阻力等指标,其中7+8、7+9亚基对拉伸面积具有正效应,Glu-A1位点的2*对沉降值、最大抗延阻力、稳定时间、形成时间和拉伸面积具有正效应;"2*,7+8,4+12"和"1,7+9,2+10"亚基组合对品质性状效应较高。     

新疆冬春麦区小麦地方品种贮藏蛋白遗传多样性研究

采用SDS-聚丙烯酰胺凝胶电泳（SDS-PAGE）对236份新疆小麦地方品种的高分子量麦谷蛋白亚基(HMW-GS)的组成进行了分析。结果表明：Glu-1位点共有19种等位基因,其中Glu-A1位点3种,Glu-B1位点7种,Glu-D1位点9种;亚基null、7+8、2+12在各自的位点上出现频率最高,分别达到91.95％、85.17％、80.93％;亚基组成类型共有21种,主要为null/7+8/2+12,频率达70.34％;同时筛选出33份含有1、2*、13+16、14+15、5+10、1.5+10、17+18等优质亚基的材料,可作为优质基因源。利用酸性聚丙烯酰胺凝胶电泳（A-PAGE）对其中的65份地方品种进行醇溶蛋白多样性分析。结果表明：电泳出现64条迁移率不同的谱带,构成65种组合,其中ω区出现的谱带最多,达17条,其次是β和γ区各16条,α区出现的谱带数最少,为15条。从每条谱带在65份材料中出现的频率看,总的变异范围为1.54%~93.85%;α、β、γ和ω四个分区多样性指数（H′）分别为0.498、0.386、0.523和0.348。这表明新疆麦区小麦地方品种贮藏蛋白位点存在丰富的遗传多样性。     

Analysis of dough functionality of flours from transgenic wheat

The rheological properties of flours from five different lines of transgenic wheat that either express or over-express subunits 1Ax1 and 1Dx5 were analyzed by mixograph assays and SDS sedimentation tests. In one case, the over-expression of subunit 1Dx5 resulted in a ca. 2-fold increase in mixing time, associated with a significant improvement in dough strength, and a lower resistance breakdown, suggesting an important increase in dough stability. However, the flour failed to develop properly without mixing with control flour because the rate of mixing was insufficient to develop the dough, i.e., the flour was overstrong. In two wheat transgenic lines, the expression of 1Ax1 and 1Dx5 transgenes, associated with silencing of all the endogenous high-molecular-weight glutenin subunits, resulted in flours with lower mixing time, peak resistance and sedimentation volumes, suggesting a lower gluten strength.     

Development of genetically modified wheat to assess its dough functional properties

End-use functionality of bread wheat depends mainly on the protein content, the presence of particular subunits of high and low molecular weight glutenin, the ratio of high molecular weight to low molecular weight glutenin subunits, and the ratio of glutenin to gliadin. The exact contribution of each of these factors to end-use functionality is still largely unknown. Transgenic plants can allow these factors to be studied within a particular background thus contributing to our understanding of end-use functionality. Two Canadian wheat lines, one of them containing high molecular weight glutenin subunits (HMW-GS) coded by all three Glu-1 loci and one line null at all three loci were assessed for dough rheological properties and bread and tortilla-making properties. Protein composition of the flours were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis, size exclusion high performance liquid chromatography, and sedimentation test. Proteins in the samples were fractionated and the proportions of monomeric proteins, soluble glutenin, and insoluble glutenin were quantified. Functionality of the flours were characterized by small-scale methods such as the 2 g mixograph, 10 g farinograph, and micro-extension testing. End-use quality was evaluated by small-scale bread and tortilla production. Mixograph development time and mixograph peak height were much higher for the lines containing HMW-GS. The lines null for HMW-GS showed no resistance to extension. Lines null for HMW-GS produced 'brick'-like bread. Tortilla prepared from the null lines had poor rollability and lower puncture force. The results showed very strong dependencies of quality on the presence of HMW-GS.     

小麦高分子量谷蛋白亚基对加工品质影响的效应分析

分析了 2 50份小麦材料的高分子量谷蛋白亚基 (HMW- GS)组成以及其中 66份材料的加工品质及面条制作品质。回归分析表明 :HMW- GS与 1 0种加工品质性状均有显著的线性关系。不同亚基对综合品质效应的得分大小依次为 :Glu- Al,1 >2 * >null;Glu- Bl,1 4 +1 5>7+8>1 7+1 8>>7+9;Glu- Dl,5+1 0 >>2 +1 2 >4+1 2。不同基因位点对品质的贡献大小顺序为 :Glu- Dl>Glu- Al>Glu- Bl。首次提出了 HMW- GS综合品质评分系统     

A cysteine in the repetitive domain of a high-molecular-weight glutenin subunit interferes with the mixing properties of wheat dough

The quality of wheat (Triticum aestivum L.) for making bread is largely due to the strength and extensibility of wheat dough, which in turn is due to the properties of polymeric glutenin. Polymeric glutenin consists of high- and low-molecular-weight glutenin protein subunits linked by disulphide bonds between cysteine residues. Glutenin subunits differ in their effects on dough mixing properties. The research presented here investigated the effect of a specific, recently discovered, glutenin subunit on dough mixing properties. This subunit, Bx7.1, is unusual in that it has a cysteine in its repetitive domain. With site-directed mutagenesis of the gene encoding Bx7.1, a guanine in the repetitive domain was replaced by an adenine, to provide a mutant gene encoding a subunit (MutBx7.1) in which the repetitive-domain cysteine was replaced by a tyrosine residue. Bx7.1, MutBx7.1 and other Bx-type glutenin subunits were heterologously expressed in Escherichia coli and purified. This made it possible to incorporate each individual subunit into wheat flour and evaluate the effect of the cysteine residue on dough properties. The Bx7.1 subunit affected dough mixing properties differently from the other subunits. These differences are due to the extra cysteine residue, which may interfere with glutenin polymerisation through cross-linkage within the Bx7.1 subunit, causing this subunit to act as a chain terminator.     

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。     

Molecular detection of QTLs for agronomic and quality traits in a doubled haploid population derived from two Canadian wheats (Triticum aestivum L.)

Development of high-yielding wheat varieties with good end-use quality has always been a major concern for wheat breeders. To genetically dissect quantitative trait loci (QTLs) for yield-related traits such as grain yield, plant height, maturity, lodging, test weight and thousand-grain weight, and for quality traits such as grain and flour protein content, gluten strength as evaluated by mixograph and SDS sedimentation volume, an F₁-derived doubled haploid (DH) population of 185 individuals was developed from a cross between a Canadian wheat variety “AC Karma” and a breeding line 87E03-S2B1. A genetic map was constructed based on 167 marker loci, consisting of 160 microsatellite loci, three HMW glutenin subunit loci: Glu-A1, Glu-B1 and Glu-D1, and four STS-PCR markers. Data for investigated traits were collected from three to four environments in Manitoba, Canada. QTL analyses were performed using composite interval mapping. A total of 50 QTLs were detected, 24 for agronomic traits and 26 for quality-related traits. Many QTLs for correlated traits were mapped in the same genomic regions forming QTL clusters. The largest QTL clusters, consisting of up to nine QTLs, were found on chromosomes 1D and 4D. HMW glutenin subunits at Glu-1 loci had the largest effect on breadmaking quality; however, other genomic regions also contributed genetically to breadmaking quality. QTLs detected in the present study are compared with other QTL analyses in wheat.     

烟草花粉原生质体与叶肉原生质体的融合及培养早期变化

用ＰＥＧ—高Ｃａ高ＰＨ法诱导抗卡那霉素的烟草（Ｎｉｃｏｔｉａｎａｔａｂａｃｕｍ）品系Ｎ３６４＋Ｋｍ＋花粉原生质体和黄花烟草（Ｎｉｃｏｔｉａｒｕｓｔｉｃａ）叶肉原生质体融合。幼嫩花粉原生质体和叶肉原生质体之间的融合体培养启动胚胎发生分裂,经卡那霉素筛选后,少数多细胞团存活并形成小愈伤组织。成熟花粉原生质体与叶肉原生质体之间的融合体则仅产生管状结构。这一结果表明,作为融合一方的花粉原生质体的发育时期对融合产物的发育途径有重要影响。     

云南铁壳麦高分子量麦谷蛋白亚基组成及其遗传多样性分析

以36份云南铁壳麦为试验材料,采用SDS-PAGE法分析了Glu-1位点编码的高分子量麦谷蛋白亚基(HMW-GS)及组成。结果表明,在Glu-A1位点上检测到3种(N,2*和1)亚基类型,Glu-B1位点上共检测到5种(7、7 8、17 18、13 16和6 8)亚基类型,Glu-D1位点上只检测到1种(2 12)亚基类型。共检测到6种亚基组成类型,即:N、7、2 12,N、7 8、2 12,2*、7 8、2 12,2*、17 18、2 12,1、6 8、2 12和1、13 16、2 12。云南铁壳麦的HMW-GS为普通小麦已知变异类型的18%,3个位点的Nei's遗传变异系数顺序为Glu-B1(0.5734)>Glu-A1(0.2484)>Glu-D1(0),表明云南铁壳麦属较原始类型,Glu-D1位点未发生变异。品质评分最高分为8分(3份材料),平均为5.2分。同时86%的云南铁壳麦具有适合制作优质手工馒头的高分子量麦谷蛋白亚基(N和2 12),42%的云南铁壳麦具有亚基组成类型(1、7 8、2 12和N、7 8、2 12),这些材料可作为云南小麦馒头品质改良的材料。     

Production and characterization of a transgenic bread wheat line over-expressing a low-molecular-weight glutenin subunit gene

The end-use properties, and thus the value, of wheat flours are determined to a large extent by the proteins that make up the polymeric network called gluten. Low molecular weight glutenin subunits (LMW-GS) are important components of gluten structure. Their relative amounts and/or the presence of specific components can influence dough visco-elasticity, a property that is correlated with the end-use properties of wheat flour. For these reasons, manipulation of gluten dough strength and elasticity is important. We are pursuing this goal by transforming the bread wheat cultivar Bobwhite with a LMW-GS gene driven by its own promoter. Particle bombardment of immature embryos produced several transgenic lines, one of which over-expressed the LMW-GS transgene. Southern blots confirmed that the transgene was integrated into the wheat genome, although segregation analyses showed that its expression was sometimes poorly transmitted to progeny. We have determined that the transgene-encoded LMW-GS accumulates to very high levels in seeds of this line, and that it is incorporated into the glutenin polymer, nearly doubling its overall amount. However, SDS sedimentation test values were lower from the transgenic material compared to a non transgenic flour. These results suggest that the widely accepted correlation between the amount of the glutenin polymers and flour technological properties might not be valid, depending on the components of the polymer.