小麦高分子量谷蛋白亚基缺失品质效应研究进展
Review on the Effects of High-Molecular-Weight Glutenin Subunit Deletions on Wheat Quality
通讯作者:
收稿日期: 2020-02-28 修回日期: 2020-03-8 网络出版日期: 2020-10-15
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Received: 2020-02-28 Revised: 2020-03-8 Online: 2020-10-15
作者简介 About authors
张晓,主要从事小麦育种研究,E-mail:
高分子量谷蛋白亚基(high-molecular-weight glutenin subunits,HMW-GS)是小麦籽粒贮藏蛋白的重要组成成分,其数量和质量与品质密切相关。聚合优质HMW-GS可改良强筋小麦制品面包品质,相反HMW-GS缺失可能在弱筋小麦制品饼干、糕点或其他特色食品品质改良上具有重要应用价值。本文从小麦HMW-GS缺失的类型和机制、贮藏蛋白组分和蛋白体发育、面粉和面团品质效应以及食品加工品质改良等方面进行了综述,分析了当前小麦HMW-GS缺失研究利用中存在的问题,并对未来研究方向进行了展望。
关键词:
High-molecular-weight glutenin subunits (HMW-GSs) are important components of storage protein in wheat grains. Wheat quality is directly influenced by composition and quantity of HMW-GSs. People generally attach importance to the improvement of bread quality of strong gluten wheat products by polymerization of high-quality HMW-GSs. On the contrary, the HMW-GS deletions may provide an important application value for improvement of biscuit and pastry of weak gluten wheat products or other traits food quality. In this paper, the types and mechanisms of HMW-GS deletions and the effects of HMW-GS deletions on storage protein components, development of protein body, flour and dough quality, and improvement of food processing quality are reviewed. Besides, the problems in current research and utilization of HMW-GS deletions are analyzed, and the future research directions are prospected.
Keywords:
本文引用格式
张晓, 李曼, 陆成彬, 吴宏亚, 江伟, 高德荣.
Zhang Xiao, Li Man, Lu Chengbin, Wu Hongya, Jiang Wei, Gao Derong.
开放科学(资源服务)标识码(OSID):
HMW-GS由染色体1A、1B和1D长臂上的位点控制,总称为Glu-1位点,分别用Glu-A1、Glu-B1和Glu-D1表示[6,7,8]。其中每个位点都有2个紧密连锁的基因,分别控制分子量较高的X-型亚基和分子量较低的Y-型亚基。理论上,每个小麦品种存在6个高分子量谷蛋白亚基,但1Ay亚基通常不表达,其他位点亚基也有不表达的情况,所以在六倍体小麦中一般存在3~5个HMW-GS[6,7,8]。然而人们普遍重视通过聚合优质HMW-GS进行强筋小麦制品面包品质的改良,却对HMW-GS缺失在弱筋小麦制品饼干、糕点或其他特色食品品质改良上可能具有的重要应用价值重视不够。本研究对小麦HMW-GS缺失的类型、机制和品质效应进行综述,以期为不同HMW-GS位点品质效应的研究和HMW-GS缺失在小麦品质改良中的应用提供参考。
1 HMW-GS缺失类型及机制
1.1 HMW-GS的多态性
1.2 HMW-GS缺失类型
自然界天然存在的HMW-GS缺失材料很少。普通小麦中1Ay亚基通常不表达;Glu-D1编码的HMW-GS仅有极少缺失。刘悦等[13]发现四川白麦子地方品种“奉节罗汉麦”Glu-D1x亚基缺失;董永梅等[14]在小麦地方品种红花须须麦中检测到了Glu-D1y亚基缺失;杨恩年等[15]在普通小麦中检测到Glu-A1和Glu-B1编码的HMW-GS共同缺失。Lawrence等[16]利用缺失系Olympic(GIu-B1位点缺失)和Gabo(Glu-A1和Glu-D1位点缺失)创造出HMW-GS表达数量由5到0的品系,形成了分别单独缺少Glu-A1、Glu-B1和Glu-D1,共同缺少Glu-A1和Glu-B1、共同缺少Glu-A1和Glu-D1以及同时缺少Glu-A1、Glu-B1和Glu-D1位点亚基的株系。Payne等[6]获得了一套类似的缺失突变体材料,HMW-GS数量从5到2。国内外研究人员陆续利用化学诱变、辐射处理、离子束辐射诱变或转基因方式获得了大量HMW-GS突变体。
1.3 HMW-GS缺失机制
正常表达的HMW-GS基因编码区均无内含子。HMW-GS的DNA编码序列由4个区域组成:(1)信号肽序列,起始密码子开始的一段63bp的核苷酸序列;(2)无重复的5′N-末端;(3)中央重复区,基因DNA序列长度的差异,主要由基因中部重复序列大小及重复次数不同引起,其变异由该区域内DNA序列的插入或缺失造成[17];(4)无重复的3'C-末端。2个紧密相连的终止密码子TGATAG终止编码。由HMW-GS的DNA序列推导出的氨基酸序列可以看出,成熟高分子量谷蛋白亚基包括3个区域:N-端非重复区,由81~104个氨基酸组成;高度重复的中央区,由400~670个氨基酸组成;C-端非重复区,由42个氨基酸组成[5]。
在HMW-GS基因编码区,已报道3种方式可导致HMW-GS基因沉默。一是转座子插入导致编码失活,如Gu等[18]报道8.6kb LTR Retrotransposon的插入导致1Ay基因沉默。二是编码区出现提前终止密码子。普通小麦中1Ay基因沉默是终止密码子提前出现的结果[19]。小偃54的1Bx14缺失后基因长度同野生型一致,但在1 402bp处C转化为T,在基因的中间重复区引入1个终止密码子[20];小偃54的1By15缺失后基因长度同野生型一致,在核苷酸序列上与野生型有1个碱基的差异(C1780 T),在基因的中间重复区引入1个终止密码子[21]。HMW-GS基因中C突变成T(CAA---TAA)会导致亚基发生沉默;在小麦高分子量麦谷蛋白基因中,由三联体密码CAA或CAG编码的谷氨酰胺(Gln)残基比例高达30%~35%,这2个三联体密码如发生C→T的单核苷酸替换都会突变成终止密码子TAA或TAG。提前终止密码子在小麦HMW-GS基因沉默中扮演重要角色,而且该沉默机制都是由C→T单核苷酸替换造成。有些研究者也提出了其他的机制。Yuan等[22]研究表明,1By亚基缺失突变体云南铁壳麦(AS332)和西藏半野生小麦(AS908)由于编码Gln的三联体密码CAA缺失了1个A,导致核苷酸序列发生移码突变,致使在编码区的下游出现多个提前终止密码子而使基因沉默。1Bx7亚基序列在55bp处缺失1个碱基A,导致在273bp处出现终止密码子TGA,蛋白翻译提前终止,进而出现1Bx7亚基缺失[23]。郑雯[24]发现野生二粒小麦D1的Ay基因的编码区仅在N-末端出现唯一的提前终止密码子,而非出现在中央重复区;野生二粒小麦D100的Ay基因序列编码区451bp处却发现提前终止密码子是由A-T的单核苷酸替换所致,即三联体密码AAA突变成终止密码子TAA。三是较大DNA片段缺失。李宁[25]研究表明,1Dx2+1Dy12亚基缺失突变体Glu-D1位点附近较大DNA片段缺失导致了1Dx2+1Dy12蛋白亚基完全缺失。
2 HMW-GS缺失对贮藏蛋白组分和蛋白体发育的影响
Uthayakumaran等[26]研究表明,HMW-GS三位点全缺失系的蛋白质含量无显著变化,但单体蛋白含量增加30%,不溶性蛋白含量下降。Don等[27]研究认为谷蛋白大聚合体(glutenin macropolymer,GMP)含量和粒度随HMW-GS亚基数目减少而降低。张平平等[28,29]和张纪元等[30]对多份HMW-GS单位点或双位点缺失材料研究表明,Glu-1位点缺失小麦籽粒中不溶性谷蛋白聚合体(UPP)含量降低,HMW-GS/LMW-GS比率下降;同时利用EMS诱变处理宁麦9号获得不同单亚基缺失突变体,结果表明,GMP含量、谷蛋白/醇溶蛋白和HMW-GS/LMW-GS比值较野生型降低。Ma等[31]利用病毒诱导产生了1Bx14亚基沉默材料,其总蛋白含量、谷蛋白含量和GMP含量均显著降低。Zhu等[32]研究了HMW-GS与蛋白体形成的关系,表明HMW-GS数量越多,蛋白体数量也越多,同时蛋白体直径与HMW-GS表达水平有关,低HMW-GS含量材料的蛋白体颗粒较小,如HMW-GS全缺失材料中蛋白体直径不大于6μm。Liu等[33]和刘会云等[34]研究表明,1Bx20和1By20缺失对胚乳蛋白体形成没有明显影响,但一定程度上刺激了多数蛋白质合成和加工相关基因表达,保证了种子内蛋白含量、蛋白体外形和大小基本不变,表现负反馈调节效应。Gao等[35]研究发现1Ax1或1Dx2缺失后谷蛋白聚合体积累率降低,导致谷蛋白聚合体快速积累时期至少推迟10d,最终成熟籽粒中不溶性谷蛋白大聚体百分比较低。Yang等[36]报道Glu-A1、Glu-B1或Glu-D1分别缺失后HMW-GS和LMW-GS含量均降低,而醇溶蛋白含量升高。
3 HMW-GS缺失对面粉和面团品质的影响
Uthayakumaran等[26]研究表明,与对照相比HMW-GS全缺失转基因系的面筋强度显著降低,揉混仪峰值高度和峰值宽度大幅下降,拉伸阻力和延伸度等拉伸仪参数也显著降低。李宁[25]在冀92-3235幼胚组织培养过程中进行辐射处理,筛选到1Dx2+1Dy12亚基缺失突变体,与对照相比其粗蛋白质含量没有明显变化,湿面筋几乎洗不到,只在网筛上有少量残留,Zeleny沉降值下降一半。Ram等[41]研究了Glu-A1和Glu-D1位点双缺失的印度小麦地方品种,其沉淀值降低、粉质仪形成时间缩短。Yue等[42]和武茹[43]通过RNAi技术获得1Dx5亚基完全不表达转化株系,其HMW-GS含量、面筋指数、Zeleny沉淀值、粉质仪形成时间和稳定时间均显著降低。Mondal等[44]研究认为Glu-A1和Glu-D1两位点共同缺失揉混仪峰值时间和峰值高度显著降低,面团弹性降低,延展性增加。含有1Bx7亚基种质材料的吸水率、湿面筋、蛋白含量、稳定时间、形成时间和沉降值等明显高于1Bx7亚基缺失材料[23]。Zhang等[45]利用离子束诱变小偃81产生HMW-GS 3个位点Glu-A1、Glu-B1和Glu-D1分别单独缺失的材料,其中Glu-A1基因型SDS沉淀值、粉质仪和揉混仪特性比对照小偃81略有增加,Glu-B1和Glu-D1基因型SDS沉淀值和面团质量比对照小偃81显著降低,以Glu-D1下降幅度最大。张平平等[28,29]利用不同HMW-GS缺失突变体研究表明Glu-A1单缺失、Glu-D1单缺失以及Glu-A1和Glu-D1双缺失显著降低了面团弹性,提高了面团延展性;同时利用EMS诱变处理宁麦9号产生Glu-A1x、Glu-B1x、Glu-B1y、Glu-D1x和Glu-D1y缺失系,经研究缺失材料的蛋白质含量、籽粒硬度和溶剂保持力等籽粒品质未显著改变,但揉混仪形成时间、峰值高度和8min带宽均显著降低,以Glu-B1x和Glu-D1x缺失型表现最低。Zhang等[46]利用近等基因系研究表明,与野生型(1、7+8、2+12)和Glu-A1位点缺失(Null、7+8、2+12)基因型相比,Glu-D1位点缺失(1、7+8、Null)基因型SDS沉淀值、乳酸SRC、面筋指数、粉质仪稳定时间和吹泡仪P值显著降低,但籽粒硬度、蛋白质含量和水SRC均无显著变化。
综上所述,HMW-GS缺失后面团强度和弹性降低。在HMW-GS不同位点缺失类型中,以Glu-D1位点缺失面团强度和弹性下降最大,其次是Glu-B1位点,Glu-A1位点缺失面团强度变化不大或略有增加,进一步说明Glu-D1位点对品质的贡献最大。面团形成过程中,面粉经水化后HMW-GS和LMW-GS通过分子间二硫键作用形成纤维状谷蛋白聚合体构成面筋的骨架,醇溶蛋白则在分子内二硫键的主要作用下形成球状结构,通过非共价键与麦谷蛋白结合,充填在纤维状大分子聚合体中,谷蛋白和醇溶蛋白共同形成面筋,赋予面团粘弹性[39,47]。由此推测,HMW-GS缺失后,用以形成谷蛋白聚合体的主链结构减少,谷蛋白聚合体积累下降,面团骨架结构变弱,进一步造成了面团强度和弹性降低。
4 HMW-GS缺失对加工品质的影响
Lawrence等[16]研究发现Glu-A1、Glu-B1和Glu-D1单位点缺失、双位点缺失或三位点缺失系的蛋白质含量无变化或升高,面包烘烤品质显著下降。Beasley等[50]研究报道,随着HMW-GS亚基缺失数目增加,面包高度极显著下降,鲜面条穿刺力极显著下降,但煮熟面条的剪切力和压缩力无显著变化。Uthayakumaran等[26]利用HMW-GS三位点缺失材料制作的面包体积非常小;墨西哥薄圆饼直径显著变大,可卷性和穿刺力下降。Mondal等[44]利用Glu-A1和Glu-D1两位点共同缺失且Glu-B1位点为17+18亚基的材料制作的墨西哥薄圆饼直径比HMW-GS不缺失亲本显著增大,但产品货架稳定性差、易碎;Glu-B1位点缺失,Glu-D1位点具5+10亚基或同时Glu-A1位点具有1亚基材料可改善墨西哥薄圆饼直径,同时具有较好的货架稳定性。Zhang等[51]研究表明,部分HMW-GS缺失类型(2*,17+_,5+_)和(2*,17+_,2+12)表现中等面团强度和强延展性,制作的馒头品质好;同时发现HMW-GS单亚基缺失系糖酥饼干直径较野生型显著增加[30]。Liu等[33]和刘会云等[34]报道1Bx20和1By20缺失引起面团和面包加工品质下降。Zhang等[46]利用近等基因系群体研究表明,与Glu-A1缺失和野生型(1,7+8,2+12)相比,Glu-A1、Glu-D1位点双缺失和Glu-D1位点单缺失均显著增加曲奇饼干直径和酥脆性。
综上所述,单个或多个HMW-GS位点缺失后面包烘烤品质均显著下降;Glu-A1和Glu-D1位点双缺失材料制作的墨西哥薄饼直径显著增加,货架稳定性差,易碎,Glu-B1位点缺失且Glu-D1位点具5+10亚基可改善墨西哥薄饼直径,同时具有较好的货架稳定性。Glu-B1x、Glu-B1y和Glu-D1y单亚基缺失或Glu-D1位点缺失显著增加饼干直径。Glu-B1或Glu-D1位点部分单亚基缺失材料制作馒头品质显著改良。
5 研究展望
综合上述研究,小麦HMW-GS缺失并未显著改变蛋白质含量和籽粒硬度;蛋白质含量无显著变化,可能与低分子量谷蛋白以及醇溶蛋白补偿升高有关[36];籽粒硬度无显著变化,是由于小麦硬度和HMW-GS基因位于不同染色体[48]。小麦HMW-GS单亚基、单位点或多位点缺失后,GMP含量降低,谷蛋白/醇溶蛋白比例下降,HMW-GS/LMW-GS比率下降,面团强度和弹性降低;Glu-D1位点缺失面团强度和弹性下降幅度最大,其次是Glu-B1位点,Glu-A1位点缺失面团强度变化不大或略有增加。单个或多个HMW-GS位点缺失后面包烘烤品质均显著下降;Glu-A1和Glu-D1位点双缺失且Glu-B1位点携17+18亚基材料制作的墨西哥薄饼直径显著增加,但货架稳定性差,易碎,Glu-B1位点缺失且Glu-D1位点具5+10亚基可改善墨西哥薄饼直径,同时具有较好的货架稳定性;Glu-B1x、Glu-B1y和Glu-D1y单亚基缺失或者Glu-D1位点缺失显著增加饼干直径;Glu-B1或Glu-D1位点1或2个Glu-1y亚基缺失制作馒头品质显著改良。
不同研究所用HMW-GS缺失材料的遗传背景存在差异,在具体分析应用时需要考虑到HMW-GS缺失与其他品质相关基因组合的影响。高分子量谷蛋白、低分子量谷蛋白和醇溶蛋白是面筋蛋白的主要成分,3种组分的亚基类型和含量,以及HMW/LMW和Glu/Gli比例与小麦加工品质密切相关[39,47]。此外,籽粒硬度也是影响面团和食品加工品质的重要因素[48,49]。当前多数HMW-GS缺失品质效应研究所用材料、遗传背景和亚基缺失类型不同,不同亚基缺失的品质效应研究结果存在差异,尤其不同HMW-GS缺失在食品中应用的探索较少,亚基缺失的品质效应及对食品品质的改良作用需进一步深入。因此,今后仍需在以下几方面进行研究:一是不同HMW-GS缺失在不同遗传背景下的品质效应,构建不同品质类型遗传背景和不同HMW-GS缺失类型(单亚基、单位点和多位点)遗传群体进行品质研究,探明不同HMW-GS缺失与不同低分子量谷蛋白亚基、醇溶蛋白亚基和不同硬度基因型组合的品质效应;二是重点进行HMW-GS缺失对弱筋小麦制品品质效应的研究,筛选出对弱筋小麦制品品质改良效应最大的亚基缺失类型和遗传背景组合;三是研究不同HMW-GS缺失的遗传和生理机制,并开发相应分子标记;四是利用不同HMW-GS缺失基因型进行新型特色食品的研发并进行市场化开发。
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PMID:24202521
[本文引用: 1]
A gene encoding the high-molecular-weight (HMW) subunit of glutenin 1Ax1 was isolated from bread wheat cv Hope. Comparison of the deduced amino acid sequence with that previously reported for an allelic subunit, 1Ax2(*), showed only minor differences, which were consistent with both subunits being associated with good bread-making quality. Quantitative analyses of total protein extracts from 22 cultivars of bread wheat showed that the presence of either subunit 1Ax1 or 1Ax2(*), when compared with a null allele, resulted in an increase in the proportion of HMW subunit protein from ca. 8 to 10% of the total. It is suggested that this quantitative increase in HMW subunit protein may account for the association of 1Ax subunits with good quality.
Diversity of grain protein and bread wheat quality:II. Correlation between high molecular weight subunits of glutenin and flour quality characteristics
DOI:10.1016/S0733-5210(85)80007-2 URL [本文引用: 1]
Functional properties of wheat glutenin
DOI:10.1006/jcrs.1996.0001 URL [本文引用: 2]
Cereal seed storage proteins:Structures,properties and role in grain utilization
DOI:10.1093/jexbot/53.370.947
URL
PMID:11912237
[本文引用: 2]
Storage proteins account for about 50% of the total protein in mature cereal grains and have important impacts on their nutritional quality for humans and livestock and on their functional properties in food processing. Current knowledge of the structures and properties of the prolamin and globulin storage proteins of cereals and their mechanisms of synthesis, trafficking and deposition in the developing grain is briefly reviewed here. The role of the gluten proteins of wheat in determining the quality of the grain for breadmaking and how their amount and composition can be manipulated leading to changes in dough mixing properties is also discussed.
Genetics of wheat storage proteins and the effect of allelic variation of bread-making quality
DOI:10.1146/annurev.pp.38.060187.001041 URL [本文引用: 3]
The prolamin storage proteins of cereal seeds:structure and evolution
DOI:10.1042/bj2670001 URL PMID:2183790 [本文引用: 2]
High molecular weight subunits of wheat glutenin
DOI:10.1016/S0733-5210(09)80062-3 URL [本文引用: 2]
Use of near-isogenic wheat lines to determine protein composition-functionality relationships
DOI:10.1094/CCHEM.2001.78.5.501 URL [本文引用: 1]
Composition of HMW and LMW glutenin subunits and their effects on dough properties,pan bread,and noodle quality of Chinese bread wheats
Allelic variation at the Glu-1 and Glu-3 loci,presence of the 1B.1R translocation,and their effects on mixographic properties in Chinese bread wheats
DOI:10.1007/s10681-005-1682-4
URL
Allelic variations at the Glu-1 and Glu-3 loci play an important role in determining dough properties and bread-making quality. Two hundred and fifty-one cultivars and advanced lines from four major Chinese wheat-producing zones in the autumn-sown wheat regions were used to investigate the high-molecular-weight glutenin subunits (HMW GS) and low-molecular-weight glutenin subunit (LMW GS) composition controlled by the Glu-1 and Glu-3 loci, respectively, as well as the presence of the 1B.1R translocation, and to determine the association of storage protein composition with protein content, SDS sedimentation value, and dough-mixing properties measured by mixograph. Three, nine, and four allelic variations were present at Glu-A1, Glu-B1, and Glu-D1, respectively. Subunits 1, N, 7+8, 7+9, and 2+12 are the dominant HMW GS, with frequencies of 51.3, 39.4, 38.2, 45.0, and 59.8%, respectively. Five and eight allelic variations were present at the Glu-A3 and Glu-B3 loci (data of Glu-D3 were not available), Glu-A3a, Glu-A3d, Glu-B3j (presence of the 1B.1R translocation), and Glu-B3d are the dominant LMW GS, with frequencies of 37.1, 31.7, 44.6, and 20.3%, respectively. The frequencies of allelic variation at Glu-1 and Glu-3 differ greatly in different regions. The effects of HMW GS and LMW GS on SDS sedimentation value, mixing time, and mixing tolerance were significant at P = 0.01, with Glu-D1 and Glu-B3 showing the largest contributions to mixing time and mixing tolerance. Averaged data from two locations showed that the quality effects of glutenin loci could be ranked as Glu-B3 > Glu-B1 > Glu-A1 > Glu-D1 > Glu-A3 for SDS sedimentation value, Glu-D1 > Glu-B3 > Glu-A1 = Glu-B1 = Glu-A3 for mixing time, and Glu-D1 > Glu-B3 = Glu-B1 > Glu-A3 > Glu-A1 for mixing tolerance, respectively. The significant and negative effect of the 1B.1R translocation on dough properties was confirmed. It was concluded that the high frequency of undesirable HMW GS and LMW GS and the presence of the 1B.1R translocation are responsible for the weak gluten property of Chinese germplasm; hence, reducing the frequency of the 1B.1R translocation and integration of desirable subunits at Glu-1 and Glu-3 such as 1, 7+8, 14+15, 5+10, Glu-A3d, and Glu-B3d, could lead to the improvement of gluten quality in Chinese wheats.]]>
Effects of allelic variation of HMW-GS and LMW-GS on mixograph properties and Chinese noodle and steamed bread qualities in a set of Aroona near-isogenic wheat lines
四川南部和重庆地区小麦地方品种的高分子量谷蛋白亚基组成分析
DOI:10.7606/j.issn.1009-1041.2006.04.151
URL
[本文引用: 1]
为进一步发掘优异基因资源,为小麦品质遗传和育种改良提供基础材料,用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)方法,对分布于四川南部及重庆地区的49种地方小麦品种进行了高分子量谷蛋白亚基(HMW—GS)组成分析。结果表明,供试小麦材料的HMW—GS组成主要有3种类型,以“Null、7+8.2+12”亚基组合出现的频率最高,说明这些地区的小麦地方品种在HMW—GS的组成上具有较高的遗传相似性,这为小麦品种中国春源于四川白麦子的说法提供了有力证据。研究还发现地方品种“奉节罗汉麦”中的Glu-IDx的编码蛋白不表达,这在中国小麦自然群体中属首次报道;同时在“南江青杆麦”的Glu-B1位点上发现了仅存在于四倍体小麦中的23+18亚基。
中国小麦代表性地方品种高分子量麦谷蛋白亚基组成分析
DOI:10.7606/j.issn.1009-1041.2007.05.201
URL
[本文引用: 1]
为了明确中国小麦地方品种的遗传多样性,并为小麦品质改良提供基础材料,利用十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)技术,分析了源自中国22个省市地区的200份代表性地方品种的高分子量麦谷蛋白亚基组成.结果表明,Glu-1位点共检测到35种亚基组合,null/7 8/2 12组合的频率最高,为59%,其它亚基组合的频率均低于10%;Glu-A1、Glu-B1和Glu-D1位点上的等位变异分别为3、12和9种,三位点中的优势亚基依次为null、7 8和2 12,其频率分别达86.5%、73.0%和85.0%.另外在Glu-B1位点上还检测到6 8 19和6 9、7、22等稀有亚基.本研究所选200份代表性地方品种的HMW-GS组成类型虽然丰富,但与品质相关的优质亚基频率较低.亚基组合得分在8分以上的品种为19个;得分在9分以上的品种有4个,它们是草鞋边(ZM011396)、中81Ⅲ-6218(ZM013120)、高8(ZM0094z8)和京红7号(ZM008935).
MacRitchie F,Wrigley C W. Dough and baking quality of wheat lines deficient in glutenin subunits controlled by the Glu-A1,Glu-B1 and Glu-D1 loci
DOI:10.1016/S0733-5210(88)80012-2 URL [本文引用: 2]
PCR analysis of genes encoding allelic variants of high molecular weight glutenin subunits at the Glu-D1 locus
DOI:10.1007/BF00225894
URL
PMID:24185923
[本文引用: 1]
Genes encoding high-molecular-weight (HMW) glutenin subunits, present in bread-wheat lines and cultivars, were studied by RFLP (restriction fragment length polymorphism) and PCR (polymerase chain reaction) analyses. In particular, allelic subunits of the x-or y-type, encoded at the Glu-D1 locus present on the long arm of chromosome 1D, were investigated. The variation in size, observed in different allelic subunits, is mainly due to variation in the length of the central repetitive domain, typical of these proteins. Deletions or duplications, probably caused by unequal crossingover, have given rise to the size heterogeneity currently observed. The possibility of using the PCR technique for a detailed analysis of HMW glutenin genes in order to obtain a more accurate estimation of the molecular weight of their encoded subunits, and the detection of unexpressed genes, is also described.
ColemanDerr D,et al. Types and rates of sequence- evolution at the high molecular weight glutenin locus in hexaploid wheat and its ancestral genomes
DOI:10.1534/genetics.106.060756
URL
PMID:17028342
[本文引用: 1]
The Glu-1 locus, encoding the high-molecular-weight glutenin protein subunits, controls bread-making quality in hexaploid wheat (Triticum aestivum) and represents a recently evolved region unique to Triticeae genomes. To understand the molecular evolution of this locus region, three orthologous Glu-1 regions from the three subgenomes of a single hexaploid wheat species were sequenced, totaling 729 kb of sequence. Comparing each Glu-1 region with its corresponding homologous region from the D genome of diploid wheat, Aegilops tauschii, and the A and B genomes of tetraploid wheat, Triticum turgidum, revealed that, in addition to the conservation of microsynteny in the genic regions, sequences in the intergenic regions, composed of blocks of nested retroelements, are also generally conserved, although a few nonshared retroelements that differentiate the homologous Glu-1 regions were detected in each pair of the A and D genomes. Analysis of the indel frequency and the rate of nucleotide substitution, which represent the most frequent types of sequence changes in the Glu-1 regions, demonstrated that the two A genomes are significantly more divergent than the two B genomes, further supporting the hypothesis that hexaploid wheat may have more than one tetraploid ancestor.
The nucleotide sequence of a HMW glutenin subunit gene located on chromosome 1A of wheat (Triticum eastivum L.)
DOI:10.1093/nar/13.19.6817
URL
PMID:2997729
[本文引用: 1]
A cloned 8.2 kb EcoRI fragment has been isolated from a genomic library of DNA derived from Triticum aestivum L. cv. Cheyenne. This fragment contains sequences related to the high molecular weight (HMW) subunits of glutenin, proteins considered to be important in determining the elastic properties of gluten. The cloned HMW subunit gene appears to be derived from chromosome 1A. The nucleotide sequence of this gene has provided new information on the structure and evolution of the HMW subunits. However, hybrid-selection translation experiments suggest that this gene is silent.
Molecular characterization of two silenced y-type genes for Glu-B1 in Triticum aestivum ssp. yunnanese and ssp. Tibetanum
DOI:10.1111/j.1744-7909.2008.00775.x
URL
[本文引用: 1]
The high-molecular-weight glutenin subunits (HMW-GSs) are a major class of common wheat storage proteins. The bread-making quality of common wheat flour is influenced by the composition of HMW-GSs. In the present study, two unexpressed 1By genes from Triticum aesitvum ssp.yunnanese AS332 and T. aesitvum ssp.tibetanum AS908 were respectively cloned and characterized. The results indicated that both of the silenced 1By genes in AS332 and AS908 were 1By9. Different from previously reported mechanisms for silenced genes 1Ax and 1Ay, which was due to the insertion of transposon elements or presence of premature stop codon via base substitution of C→T transition in trinucleotides CAA or CAG, the silence of 1By9 genes were caused by premature stop codons via the deletion of base A in trinucleotide CAA, which leaded to frameshift mutation and indirectly produced several premature stop codons (TAG) at the downstream of the coding sequence.
Development of genetically modified wheat to assess its dough functional properties
DOI:10.1023/A:1023461305848
URL
[本文引用: 3]
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.]]>
HMW-GS affect the properties of glutenin particles in GMP and thus flour quality
DOI:10.1016/j.jcs.2006.02.005 URL [本文引用: 1]
Glu-1位点缺失对小麦麦谷蛋白聚合体粒度分布及面团特性的影响
DOI:10.3724/SP.J.1006.2015.00022
URL
[本文引用: 2]
Glu-1位点正常和部分缺失的小麦品系为材料,探讨HMW-GS和LMW-GS组成与谷蛋白聚合体粒度分布和面团特性的关系,为利用HMW-GS缺失系改良小麦品质提供理论依据。在20个供试硬白冬麦品系中,1个品系为Glu-A1位点缺失,5个品系为Glu-D1缺失,3个品系为Glu-A1和Glu-D1双缺失。所有品系的蛋白质含量皆较高(13.39%~14.12%),品系间无显著差异,缺失系与非缺失系间也无显著差异。Glu-1位点缺失显著降低了高分子量谷蛋白/低分子量谷蛋白比(HMW/LMW)、不溶性谷蛋白大聚体的含量和百分比。谷蛋白/醇溶蛋白比(GLU/GLI)在基因型间变幅较小,且在缺失系和非缺失系间无显著差异。Glu-1位点缺失显著降低了面团弹性,但显著提高了面团的延展性。部分Glu-1位点缺失系仍具有较高的面团强度和突出的延展性,谷蛋白聚合体粒度分布和面团特性受谷蛋白亚基组成和表达量的共同影响。研究结果表明,利用Glu-1位点亚基缺失可能是改善面筋延展性,提高食品加工品质的方法之一。]]>
高分子量谷蛋白单亚基缺失对软质小麦宁麦9号加工品质的影响
DOI:10.3724/SP.J.1006.2016.00633
URL
[本文引用: 2]
P<0.05)。缺失型的揉面仪峰值时间和8 min带宽变异范围分别为1.38~1.64 min和3.38%~3.98%,显著低于野生型的2.00 min和4.57% (P<0.05),以Glu-B1x和Glu-D1x缺失型表现最低。与野生型相比,缺失型的糖酥饼干直径均有增加,其中Glu-B1x、Glu-B1y和Glu-D1y缺失型饼干直径的增加达显著水平(P<0.05),而缺失型之间的差异不显著。在宁麦9号背景下,高分子量麦谷蛋白单亚基缺失弱化了面筋强度,改善了糖酥饼干加工品质,亚基敲除可能是进一步提高软质小麦加工品质的有效途径。]]>
以EMS诱变创制软质小麦宁麦9号高分子量谷蛋白亚基突变体
DOI:10.3724/SP.J.1006.2014.01579
URL
[本文引用: 2]
本研究旨在创制遗传背景一致的不同高分子量谷蛋白亚基(HMW-GS)缺失系, 为小麦品质研究和育种提供材料。将软质小麦品种宁麦9号, 用0.4% EMS溶液处理10 000粒种子, 获得3781个M1代单株, 采用“半粒法”对每个株系进行SDS-PAGE鉴定, 从中筛选出299个(7.91%) HMW-GS突变株, 包括HMW-GS缺失和分子量突变两种类型。其中, HMW-GS缺失突变176株, 突变频率为4.65%, 缺失亚基涉及Ax1、Bx7、By8、Dx2和Dy12, 突变频率为0.24%~3.28%; 分子量突变130株, 突变频率为3.44%。将突变体的具胚端种子于温室中繁殖获得M2代, 再次鉴定各株系的HMW-GS, 并经M3代验证, 最终获得Ax1、Dx2、Bx7、By8和Dy12缺失突变体, 及Ax1+By8双缺失突变体。用高效液相色谱(HPLC)分析这些突变体的谷蛋白大聚体(GMP)和谷蛋白/醇溶蛋白(GLU/GLI)比值, 发现不同缺失突变体的GMP含量都有不同程度的降低, 尤以Bx7亚基缺失突变体中GMP含量降幅最大, 高达42%。另外, 不同缺失突变体的谷蛋白总量和GLU/GLI比值也低于对照, Ax1+By8双缺失突变体的GLU/GLI比值最小。
Virus-induced gene-silencing in wheat spikes and grains and its application in functional analysis of HMW-GS-encoding genes
DOI:10.1186/1471-2229-12-141 URL [本文引用: 1]
Molecular cloning,phylogenetic analysis,and expression profiling of endoplasmic reticulum molecular chaperone BiP genes from bread wheat (Triticum aestivum L.)
DOI:10.1186/s12870-014-0260-0 URL [本文引用: 1]
Comprehensive identification and bread-Making quality evaluation of common wheat somatic variation line AS208 on glutenin composition
小麦突变体AS208中Glu-B1位点缺失对籽粒中蛋白体形成和储藏蛋白合成与加工相关基因表达的影响
Effects of HMW-GS Ax1 or Dx2 absence on the glutenin polymerization and gluten micro structure of wheat (Triticum aestivum L. )
DOI:10.1016/j.foodchem.2017.07.165
URL
PMID:28946321
[本文引用: 1]
Wheat (Triticum aestivum L.) dough strength and extensibility are mainly determined by the polymerization of glutenin. The number of high-molecular-weight glutenin subunits (HMW-GS) differs in various wheat varieties due to the silencing of some genes. The effects of Ax1 or Dx2 subunit absence on glutenin polymerization, dough mixing properties and gluten micro structure were investigated with two groups of near-isogenic lines. The results showed that Ax1 or Dx2 absence decreased the accumulation rate of glutenin polymers and thus delayed the rapid increase period for glutenin polymerization by at least ten days, which led to lower percentage of polymeric protein in mature grain. Ax1 or Dx2 absence significantly decreased the dough development time and dough stability, but increased the uniformity of micro structure. Lacunarity, derived from quantitative analysis of gluten network, is suggested as a new indicator for wheat quality.
Efficient isolation of ion beam-induced mutants for homoeologousloci in common wheat and comparison of the contributions of Glu-1 loci to gluten functionality
DOI:10.1007/s00122-013-2224-4
URL
[本文引用: 3]
To efficiently conduct genetic analysis, it is beneficial to have multiple types of mutants for the genes under investigation. Here, we demonstrate that ion beam-induced deletion mutants can be efficiently isolated for comparing the function of homoeologous loci of common wheat (Triticum aestivum). Through fragment analysis of PCR products from M-2 plants, ion beam mutants lacking homoeologous Glu-A1, Glu-B1 or Glu-D1 loci, which encode high molecular weight glutenin subunits (HMW-GSs) and affect gluten functionality and end-use quality of common wheat, could be isolated simultaneously. Three deletion lines missing Glu-A1, Glu-B1 or Glu-D1 were developed from the original mutants, with the Glu-1 genomic regions deleted in these lines estimated using newly developed DNA markers. Apart from lacking the target HMW-GSs, the three lines all showed decreased accumulation of low molecular weight glutenin subunits (LMW-GSs) and increased amounts of gliadins. Based on the test data of five gluten and glutenin macropolymer (GMP) parameters obtained with grain samples harvested from two environments, we conclude that the genetic effects of Glu-1 loci on gluten functionality can be ranked as Glu-D1 > Glu-B1 > Glu-A1. Furthermore, it is suggested that Glu-1 loci contribute to gluten functionality both directly (by promoting the formation of GMP) and indirectly (through keeping the balance among HMW-GSs, LMW-GSs and gliadins). Finally, the efficient isolation of ion beam mutations for functional comparison of homoeologous loci in polyploid plants and the usefulness of Glu-1 deletion lines for further studying the contribution of Glu-1 loci to gluten functionality are discussed.]]>
A model for the molecular structure of the glutenins from wheat flour
DOI:10.1016/S0733-5210(85)80029-1 URL [本文引用: 1]
Structural studies of cereal prolamins,including wheat gluten
Genomic and functional genomics analyses of gluten proteins and prospect for simultaneous improvement of end-use and health-related traits in wheat
The biochemical and molecular basis of wheat quality//Carver B F. Wheat science and trade
Nap Hal,an Indian landrace of wheat,contains unique genes for better biscuit making quality
DOI:10.1007/BF03321979 URL [本文引用: 1]
Generation of transgenic wheat lines with altered expression levels of 1Dx5 high-molecular weight glutenin subunit by RNA interference
DOI:10.1016/j.jcs.2007.03.006
URL
[本文引用: 1]
AbstractIn recent years, high molecular weight glutenin subunit (HMW-GS) null mutants have been found to be useful for studying the contribution of HMW-GS to the flour processing quality of wheat (Triticum aestivum L. em. Thell.). However, few reports have dealt with the development and characterization of such variants. In the present study, the RNA interference (RNAi) method was applied to Bobwhite wheat, which has five actively expressed HMW-GS genes (namely 1Ax2*, 1Dx5, 1Bx7, 1By9, 1Dy10), with the aim of silencing the expression of 1Dx5. Out of the six transgenic events characterized, 1Dx5 expression was completely blocked in four transgenic events (L1–L4), and partially reduced in the other two (L5, L6). In contrast, the protein levels of 1Ax2*, 1By9 and 1Dy10 were not significantly affected in any of the six transgenic events. Interestingly, 1Bx7 protein accumulation was negatively affected in all six events and their progenies. 1Dx5 transcript levels in developing seeds at 15 days after pollination (DAP) were undetectable in L1 and dramatically reduced in L5. The silencing of 1Dx5 expression caused a substantial decrease in flour processing quality based on Farinograph, gluten and Zeleny tests. Collectively, our data suggest that RNAi is useful for silencing HMW-GS genes. The resultant transgenic lines are of value for studying the contributions of specific HMW-GS to wheat flour processing quality.]]>
Use of near-isogenic wheat lines to determine the glutenin composition and functionality requirements for flour tortillas
DOI:10.1021/jf071831s
URL
PMID:18072743
[本文引用: 2]
In wheat ( Triticum aestivum L), the synthesis of high molecular weight (HMW) glutenins (GS) is controlled by three heterologous genetic loci present on the long arms of group 1 wheat chromosomes. The loci Glu-A1, Glu-B1, and Glu-D1 and their allelic variants play important roles in the functional properties of wheat flour. This study focused on understanding the functionality of these protein subunits on tortilla quality. Near-isogenic wheat lines in which one or more of these loci were absent or deleted were used. Tortillas were prepared from each deletion line and the parent lines. The elimination of certain HMW-GS alleles alter distinct but critical aspects of tortilla quality such as diameter, shelf stability, and overall quality. Two deletion lines possessing HMW-GS 17 + 18 at Glu-B1 and deletions in Glu-A1 and Glu-D1 had significantly larger tortilla diameters, yet tortilla shelf life was compromised or unchanged from the parent lines used to develop the deletion lines or the commercial tortilla flour used as a control. Alternatively, a deletion line possessing Glu-A1 and Glu-D1 (HMW-GS 1, 5 + 10) and a deletion in Glu-B1 also significantly improved tortilla diameters. Whereas the increase in diameter was less than the line possessing only HMW-GS 17 + 18 at Glu-B1, the stability of the tortillas were, however, maintained and improved as compared to the parent lines containing a full compliment of HMW-GS. Thus, the presence of subunits 5 + 10 at Glu-D1 alone or in combination with subunit 1 at Glu-A1 appears to provide a compromise of improvement in dough extensibility for improved tortilla diameters while also providing sufficient gluten strength to maintain ideal shelf stability.
High molecular weight glutenin subunits deficient mutants induced by ion beam and the effects of Glu-1 loci deletion on wheat quality properties
DOI:10.1002/jsfa.7221
URL
PMID:25886243
[本文引用: 1]
BACKGROUND: High-molecular-weight glutenin subunits (HMW-GSs) play a critical role in determining the viscoelastic properties of wheat. Mutations induced by ion beam radiation have been applied to improve the yield and quality of crop. In this study, HMW-GS-deficient mutant lines were selected and the effects of Glu-1 loci deletion on wheat quality properties were illustrated according to the analysis of dry seeds of common wheat (Triticum aestivum L.) Xiaoyan 81 treated with a nitrogen ion beam. RESULTS: Three HMW-GS-deficient mutant lines were obtained and then detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Large-chromosome-fragment deletion resulted in specific deficiencies, and the deleted region sizes were determined using molecular markers. Agronomic characters, quantity and proportion of glutenins and dough microstructure of the deletion lines all proved to be quite different from those of wild-type Xiaoyan 81. Analysis of quality properties suggested that GluA1(-) had superior property parameters, while GluB1(-) and GluD1(-) both showed a significant decrease in quality properties compared with Xiaoyan 81. CONCLUSION: The effects of the three Glu-1 loci on flour and dough quality-related parameters should be Glu-D1 > Glu-B1 > Glu-A1. Ion beam radiation can be used as a mutagen to create new crop mutants.
Effect of high-molecular-weight glutenin subunit deletion on soft wheat quality properties and sugar-snap cookie quality estimated through near-isogenic lines
DOI:10.1016/S2095-3119(17)61729-5 URL [本文引用: 2]
小麦籽粒硬度及其分子遗传基础研究回顾与展望
籽粒硬度是最重要的小麦品质性状之一,是市场分级和定价的重要依据。随着硬度测试方法的日趋完善,其分子遗传基础的研究逐步加快。硬度主要受位于5D染色体短臂上一个主效基因和多个微效基因控制,Pina和Pinb是形成小麦籽粒硬度的基础。PINA蛋白的缺失或编码PINB蛋白的基因突变均造成小麦胚乳质地变硬。中国目前该项研究较少,与国外相比仍有很大差距,本文着重阐述了小麦胚乳结构及硬度的生化和遗传基础,旨在为我国小麦籽粒硬度的研究提供理论依据。
Discovery,distribution and diversity of Puroindoline-D1 genes in bread wheat from five countries (Triticum aestivum L.)
DOI:10.1186/1471-2229-13-211
URL
PMID:24330683
[本文引用: 2]
BACKGROUND: DAYSLEEPER is a domesticated transposase that is essential for development in Arabidopsis thaliana [Nature, 436:282-284, 2005]. It is derived from a hAT-superfamily transposon and contains many of the features found in the coding sequence of these elements [Nature, 436:282-284, 2005, Genetics, 158:949-957, 2001]. This work sheds light on the expression of this gene and localization of its product in protoplasts and in planta. Using deletion constructs, important domains in the protein were identified. RESULTS: DAYSLEEPER is predominantly expressed in meristems, developing flowers and siliques. The protein is mainly localized in the nucleus, but can also be seen in discrete foci in the cytoplasm. Using several vesicular markers, we found that these foci belong to vesicular structures of the trans-golgi network, multivesicular bodies (MVB's) and late endosomes. The central region as well as both the N- and the C-terminus are essential to DAYSLEEPER function, since versions of DAYSLEEPER deleted for these regions are not able to complement the daysleeper phenotype. Like hAT-transposases, we show that DAYSLEEPER has a functionally conserved dimerization domain [J Biol Chem, 282:7563-7575, 2007]. CONCLUSIONS: DAYSLEEPER has retained the global structure of hAT transposases and it seems that most of these conserved features are essential to DAYSLEEPER's cellular function. Although structurally similar, DAYSLEEPER seems to have broadened its range of action beyond the nucleus in comparison to transposases.
Synergistic and additive effects of three high molecular weight glutenin subunit loci. II. Effects on wheat dough functionality and end-use quality
DOI:10.1094/CCHEM.2002.79.2.301 URL [本文引用: 1]
Effect of high molecular weight glutenin subunit composition in common wheat on dough properties and steamed bread quality
DOI:10.1002/jsfa.6635
URL
[本文引用: 1]
RESULTSAlthough similar in protein content (134-140 mg g(-1)), gluten composition and dough properties differed widely among the lines. Compared with non-deletion lines, deletion lines had lower (P CONCLUSIONDeletion at Glu-B1y and/or Glu-D1y loci in high-strength hard wheat produced good dough properties for steamed bread. This suggests that wheat functionality for steamed bread can be improved by manipulating HMW-GS composition. (c) 2014 Society of Chemical Industry]]>
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