首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
The Gsp-1 genes of wheat encode two components, the “grain softness protein” (whose role in determining texture has not been substantiated) and a 15 residue arabinogalactan peptide (AGP) sequence which is O-glycosylated and is also of unknown function. We have determined genomic Gsp-1 sequences from 29 species within the Triticeae tribe and an additional 12 species from the major subfamilies of the Poaceae (Anomochlooideae, Bambusoideae, Ehrhartoideae, Chloridoideae and Panicoideae). Twelve new AGP sequence types were identified with forms present in Agropyron mongolicum, Secale cereale, Oryza sativa subsp. japonica and Sorghum bicolor containing an extra ten amino acids within the AGP sequence. Phylogenetic analysis showed distinct groupings of AGP/GSP sequence types which had no apparent relationship to the species or even the genus. However, individual forms of AGP forms were associated with specific groups of GSP sequences, providing no evidence that the AGP and GSP-1 parts of the protein have diverged at different rates or in different ways.  相似文献   

2.
3.
The aim of this study was to evaluate the cumulative and interactive effects on wheat (Triticum aestivum L.) gluten strength and mixing properties of dough associated with the duplication of the Glu-D1 locus. A partially isohomoeoallelic line RR240, in which a segment of the wheat chromosome 1D containing the Glu-D1 locus encoding the Dx2 + Dy12 subunits and translocated to the long arm of the chromosome 1A through homoeologous recombination, was assessed. Agronomic traits and yield components were studied in the translocated line RR240 and compared with the control line cv. Courtot. Both lines were evaluated under field conditions in two experimental years. Technological effects resulting from the duplication of HMW glutenin subunits Dx2 and Dy12 were evaluated using the Alveograph test, the Mixograph test and the baking test. The RR240 line was shown to have a lower agronomic performance for 1000-kernel weight and grain yield. However the duplication of the Glu-D1 allele was associated with a significant effect on dough strength and mixing resistance, and on the Zeleny sedimentation volume. Baking parameters were not significantly modified between both lines although the score values of the CNERNA test were observed to be slightly higher in RR240 than in Courtot.  相似文献   

4.
As currently practiced, genetic engineering of monocots requires the use of selective agents, such as herbicides and antibiotics, and marker genes for resistance to favor the multiplication of the initially transformed cells. In the present paper we have used “minimal gene cassettes” and positive selection to generate transgenic durum wheat lines free of herbicide and antibiotic resistance marker genes. Two biolistic transformation experiments were carried out using three “minimal gene cassettes” consisting of linear DNA fragments each excised from the source plasmids. The targeted trait genes were two bread wheat sequences encoding the Dx5 and Dy10 high-molecular-weight (HMW) glutenin subunits, which have been associated with superior bread-making quality and which are absent from durum wheats. The positive selectable marker was the Escherichia coli phosphomannose isomerase (pmi) gene, whose product catalyzes the reversible interconversion of mannose-6-phosphate and fructose-6-phosphate, allowing plant cells to utilize mannose as a carbon source. PCR assays of genomic DNA from regenerated plants identified 15 T0 plants that contained the pmi marker gene for an overall transformation efficiency of 1.5%, which is similar to biolistic transformation efficiencies of durum wheat with intact circular plasmids. Line TC-52, which initially contained pmi, non-expressed 1Dx5, and expressed 1Dy10 HMW glutenin subunit transgenes, was further investigated. PCR was used to follow inheritance of the pmi marker gene and 1Dx5 from the T1 to T3 generations. Transgene expression was monitored by the chlorophenol-red assay for pmi and SDS-PAGE of seed proteins for 1Dy10. From these analyses, we observed that the 1Dy10, 1Dx5 and pmi transgenes were not linked, allowing us in the T3 generation to identify 1Dy10 transgenic segregants that contained no marker or silent 1Dx5 transgenes. Homozygotes containing and expressing only the 1Dy10 transgene were identified in the T4 generation. These experiments show that it is possible to combine biolistic transformation by minimal gene cassettes with genetic segregation to make marker-free transgenic wheat plants with new traits.  相似文献   

5.
Alpha-amylase inhibitors are attractive candidates for the control of seed weevils as these insects are highly dependent on starch as an energy source. For weevil control, alpha-amylase inhibitors and their genes could be used to genetically engineer weevil resistant seeds. Thirty genes encoding dimeric alpha-amylase inhibitors were isolated from Triticum aestivum L. ‘Chinese Spring’ and characterized by nucleotide and amino acid sequence analysis. Eleven representative alpha-amylase inhibitor genes were identified, and the deduced amino acid sequences of these genes were of high coherence (95.1%). These inhibitors and others obtained from the wheat EST database were clustered into three groups, the genes from ‘Chinese Spring’ were present in each group. Specific primer sets were designed for each group, based on the SNPs of these genes, and the chromosome locations of each group of inhibitor genes investigated by amplification of the ‘Chinese Spring’ ditelosomic lines. There were two and one groups of inhibitor genes on chromosomes 3BS and 3DS, respectively, whereas no group of inhibitor genes was found on chromosome 3AS. Thus, the primer set for each group of inhibitor genes was genome allele-specific. The two known inhibitors, 0.53 and 0.19, were located on chromosomes 3BS and 3DS, respectively. The validity of the three genome allele-specific primer sets was confirmed by amplifications in 15 accessions of Triticum urartu, Triticum monococcum, Aegilops tauschii and Triticum dicoccoides. These results gave further support at the molecular level, that the 24 kDa dimeric alpha-amylase inhibitors in cultivated wheat are encoded by a multigene family.  相似文献   

6.
The 75K γ-secalins encoded by genes present at the locus Sec2 on chromosome 2R are unique to rye and contribute about half of all rye storage proteins. However, there is a lack of sequence information for paralogous genes in this locus. For this study, 59 γ-secalin paralogous sequences in the Sec2 locus were characterized from a cultivated rye and derived lines after crossing with bread wheat. They had similar structures with conserved sequences in their repetitive regions for the signal peptide, N-terminal, C-terminal and the repeat motif. Their high homology indicated that they originated from an ancestor sequence that existed before the speciation of the genus Secale. Duplication and divergence might have led to the formation of the paralogous genes at Sec2. Besides point mutations, these paralogs showed variations in DNA length due to insertion or deletion events in their repetitive regions. They encoded secalins with deduced molecular weight ranges between 22.2 and 54.5 kDa. These insertion or deletions may be caused by illegitimate recombination and this locus seemed to contribute to increased levels of protein content. However, the incorporation of locus Sec2 may have a negative effect on flour processing quality since it reduced the SDS-sedimentation value.  相似文献   

7.
The mixing properties of the dough are critical in the production of bread and other food products derived from wheat. The high molecular weight glutenin subunits (HMW-GS) are major determinants of wheat dough processing qualities. The different alleles of the HMW-GS genes in hexaploid wheat vary in their effect on dough quality. To determine the contribution of the individual HMW-GS alleles, lines deficient in HMW-GS proteins were generated by chemical mutagenesis in the elite bread wheat Triticum aestivum cv. Summit. In this report we describe the identification and characterization of Dy10 and Ax1 deficient lines. Examination of the effect of Dy10 and Ax1 deficiency on dough rheological properties by mixography showed shorter mixing time to reach peak resistance, and weaker and less extensible doughs relative to the wild type control. This is the first time that the role of Dy10 in vivo has been examined apart from the Dx5 + Dy10 allelic pair combination.  相似文献   

8.
Two near-isogenic lines of the wheat variety Lance having Glu-D1a (HMW-GS 2 + 12) and Glu-D1d (HMW-GS 5 + 10) were subjected to several regimes of heat stress. In 2001, the temperature regimes were (i) 20/16 (day/night, °C) from planting to maturity, (ii) 20/16 except for a 3-day heat treatment of 35/20, 25 days after anthesis and (iii) 20/16 until 25 DAA, after which plants were subjected to 40/25 until maturity. In 2002, treatments (i) and (iii) were the same while treatment (ii) used a temperature of 40/25 °C for 3 days at 25 DAA. Seed was collected at 3-day intervals starting from 16 days after anthesis and analyzed for protein composition by SE-HPLC. The line with the Glu-D1d allele showed an earlier polymerization of glutenin than its allelic counterpart and a higher molecular weight of glutenin at maturity, this being deduced from measurements of the percentage of unextractable polymeric protein. It is postulated that the timing and rate of glutenin polymerization, and the timing of high temperature application may be the key factors contributing to an explanation of the effect of heat stress on functionality.  相似文献   

9.
Grain hardness, a major determinant influencing end-use quality of common wheat, is mainly controlled by Puroindoline a-D1 (Pina-D1) and Puroindoline b-D1 (Pinb-D1) genes. Recently, additional puroindoline genes, designated Puroindoline b-2 (Pinb-2), were described. This study examined frequencies of Pin-D1 alleles and Pinb-2 variants in 94 West European wheat genotypes and assessed their association with 13 quality traits considering population and family structure. The survey was completed by analyzing the Grain softness protein-1 gene. Results indicated sequence variation only for Pinb-D1 and Pinb-B2 genes. Pinb-D1b was the predominant hard allele. Pinb-B2v3-1 was the most common Pinb-2 variant, followed by a newly discovered variant Pinb-B2v3-5. Association mapping carried out in the whole sample population showed that Pinb-D1 alleles were associated with 11 quality traits, whereas Pinb-B2 variants were only associated with semolina extraction. Considering only the panel of hard wheat genotypes, variation for flour ash content, sedimentation value, gluten index and loaf volume was found to be associated with Pinb-D1 mutations suggesting that different Pinb-D1 mutations might have particular effects on quality traits. Our study indicated that Pinb-D1d was associated with inferior sedimentation value, gluten index and loaf volume, for which reason this mutation should be disregarded in breeding for quality wheat.  相似文献   

10.
Grain protein concentration (GPC) affects wheat nutritional value and several critical parameters for bread and pasta quality. A gene designated Gpc-B1, which is not functional in common and durum wheat cultivars, was recently identified in Triticum turgidum ssp. dicoccoides. The functional allele of Gpc-B1 improves nitrogen remobilization from the straw increasing GPC, but also shortens the grain filling period resulting in reduced grain weight in some genetic backgrounds. We developed isogenic lines for the Gpc-B1 introgression in six hexaploid and two tetraploid wheat genotypes to evaluate its effects on bread-making and pasta quality. In common wheat, the functional Gpc-B1 introgression was associated with significantly higher GPC, water absorption, mixing time and loaf volume, whereas in durum wheat, the introgression resulted in significant increases in GPC, wet gluten, mixing time, and spaghetti firmness, as well as a decrease in cooking loss. On the negative side, the functional Gpc-B1 introgression was associated in some varieties with a significant reduction in grain weight, test weight, and flour yield and significant increases in ash concentration. Significant gene × environment and gene × genotype interactions for most traits stress the need for evaluating the effect of this introgression in particular genotypes and environments.  相似文献   

11.
In this work we report the effects of the HMW-GS 1Ax1, 1Dx5 and 1Dy10 on the breadmaking quality of the bread wheat cultivar Anza that contains the HMW-GS pairs 1Dx2 + 1Dy12 and 1Bx7* + 1By8, and is null for the Glu-A1 locus. This allows the characterization of individual subunits 1Dx5 and 1Dy10 in the absence of subunit 1Dx5, and the interactions between these subunits and subunits 1Dx2 and 1Dy12 to be determined. Three transgenic lines termed T580, T581 and T590, containing, respectively, the HMW-GS 1Ax1, 1Dx5 and 1Dy10 were characterized over 3 years using a range of widely-used grain and dough testing methods. The transgenic subunits 1Ax1, 1Dx5 and 1Dy10 accounted for 25.2%, 20.3% and 17.9%, respectively, of the total HMW-GS in the three transgenic lines. Although lines T581 and T590 expressed similar levels of subunits 1Dx5 and 1Dy10 they had different effects on other aspects of protein composition, including changes in the ratios of glutenin/gliadin, of HMW/LMW-GS, the 1Dx2/1Dy12, the x-type/y-type HMW-GS and the proportions of high molecular mass glutenin polymers. In contrast, lines transformed to express subunits 1Ax1 and 1Dx5 showed similar changes in protein composition, with higher protein contents and decreased ratios of glutenin/gliadin and 1Dx2/1Dy12. In addition, both transgenic lines showed similar increases in the ratio of x-type/y-type subunits compared to the control line. The transgenic lines were analysed using Farinograph, Mixograph and Alveograph. This confirmed that the expression of all three subunits resulted in increased dough strength (and hence breadmaking quality) of the cultivar Anza. A beneficial effect of subunit 1Dx5 has not been reported previously, transgenic wheat lines expressing this subunit giving overstrong dough unsuitable for breadmaking. However, the expression of subunit 1Dy10 had a greater effect on breadmaking quality than subunits 1Ax1 and 1Dx5. The Farinograph parameters such as dough stability and peak time were increased by 9.2-fold and 2.4-fold, respectively, in line T590 (expressing 1Dy10) with respect to the control line. Similarly, the Mixograph mixing time was increased by four-fold and the resistance breakdown decreased by two-fold in line T590 compared with the control line. The Alveograph W value was also increased by 2.7-fold in line T590 compared to the control line. These transgenic lines are of value for studying the contribution of specific HMW-GS to wheat flour functional properties.  相似文献   

12.
The concentration of yellow carotenoid pigments in durum wheat grain is an important quality criterion and is determined both by their accumulation and by their degradation by lipoxygenase enzymes (Lpx loci). The existence of a duplication at the Lpx-B1 locus and the allelic variation for a deletion of the Lpx-B1.1 copy is reported. This deletion was associated with a 4.5-fold reduction in lipoxygenase activity and improved pasta color (P<0.0001) but not semolina color, suggesting reduced pigment degradation during pasta processing. A molecular marker for the deletion was mapped on chromosome 4B in a population obtained from the cross between durum line UC1113 and variety Kofa. A second lipoxygenase locus, designated Lpx-A3, was mapped on the homoeologous region on chromosome 4A and was associated with semolina and pasta color (P<0.01) but not with lipoxygenase activity in the mature grain. Selection for both the UC1113 allele for Lpx-A3 and the Kofa Lpx-B1.1 deletion resulted in a 10% increase in yellow scores for dry pasta relative to the opposite allele combination. This result indicates that the markers and the new allelic variants reported here will be useful tools to manipulate the wheat Lpx loci and to improve pasta color.  相似文献   

13.
The puroindoline genes Pina-D1 and Pinb-D1 located at the Ha locus on chromosome 5D of common wheat are considered the most important genetic determinants of grain hardness. The recent identification of Pinb-2 genes on group 7 chromosomes emphasises the need for detailed analysis of the genetics of this important trait. This study focussed on the analysis of Pinb-2 genes from accessions of hexaploid, tetraploid and diploid wheat, to address key questions related to their diversity and possible roles. Extensive DNA sequence heterogeneity was identified in the form of single nucleotide polymorphisms (SNPs), leading to seventeen reproducible haplotypes, of which thirteen are new. The results confirmed the known groups Pinb-2v1 to Pinb-2v5, identified a new group Pinb-2v6, and showed that the Pinb-2 genes comprised a small multigene family, at least in some genomes. The putative proteins exhibited changes at the important tryptophan-rich domain as well as basic and hydrophobic residues. A new Pina-D1 allele (at Ha locus) was also identified, designated Pina-D1t, with a premature stop codon at the TRD. Additionally, peptides designed on PINB-2 proteins displayed activity against bacteria and phytopathogenic fungi. The data strongly support the Pinb-2 genes being functionally relevant to roles including influencing grain texture.  相似文献   

14.
为了给ISSR标记技术应用于小黑麦杂种鉴定提供参考,利用ISSR标记对小黑麦品系P1和P_2有性杂交得到的F_1代群体进行分子鉴定,同时结合田间表型调查结果对F_1代群体进行遗传多样性分析。结果表明,66个杂交F_1代单株中,52个为真杂种,其中,5个单株无主茎、未结实,1个生长后期死亡。14条ISSR引物对46个正常结实真杂种扩增的多态性条带百分率为61.19%,其中,UBC822的多态性条带百分率为100%,UBC808和UBC815的多态性条带百分率均为75%。F_1代群体和父母本的遗传相似系数为0.62~0.94,说明杂交后代产生了丰富的遗传变异。聚类分析将杂交F_1代群体和父母本在阈值0.748处分为3大类群,第1类群包括1份材料(父本,P1),第2类群包括1份材料(母本,P_2),第3类包括46个杂交F_1代单株;杂交F_1代与父母本的遗传距离较远,先与母本聚为一类,之后与父本聚为一类。田间调查结果表明,7个性状中,除株高偏向于父本外,分蘖数、有效分蘖数、穗长、小穗数、穗粒数和穗粒重均偏向于母本,与父本的差距较大,这与ISSR分析结果基本相吻合。  相似文献   

15.
The low molecular weight glutenin subunits (LMW-GS) are wheat storage proteins participating to the formation of glutenin polymers that, along with the other gluten proteins, allow the accumulation of a large quantity of protein in the endosperm tissue. The size and composition of the glutenin polymers are directly related to gluten visco-elastic properties. In particular, LMW-GS composition is the factor most influencing durum wheat quality.  相似文献   

16.
Cloning and functional analysis of high molecular weight wheat glutenin subunit (HMW-GS) 1By8 from Italy durum cultivar Simeto was carried out in this study. All HMW-GS from Simeto were separated and characterized by appropriate electrophoresis methods, reversed-phased high performance liquid chromatography (RP-HPLC) and mass spectrometry (MS). The complete gene encoding 1By8 subunit was amplified by allele-specific PCR primers, including an upstream sequence of 857 bp and an open reading frame (ORF) of 2166 bp encoding a mature protein of 720 amino acid residues. The promoter sequence, containing -300 element (cereal glutenin gene control element) and enhancer was highly conserved among HMW-GS genes. Comparison with the sequence of subunit 1By9 from bread wheat demonstrated 99% identity with the main difference being that the 1By8 subunit possesses an additional insertion of 15 amino acid residues (QYPASQQQPA QGQQG) at position 342 and two residue substitutions at position 78 (leucine/proline) and 442 (arginine/glutamine). The molecular weight differences between MALDI-TOF-MS and deduced amino acid sequence of the coding gene revealed the possibility of some kinds of post-translational modifications present in 1By8 subunit. The protein subunit expressed in Escherichia coli showed a very similar mobility to the endogenous 1By8 of Simeto on SDS-PAGE. The function of the isolated protein on wheat processing quality was determined by 10 g Mixgraph analysis. Results demonstrated that addition of y-type HMW glutenin subunits into the base flour had significant positive effects on main mixing parameters and significant difference in effects were observed among different y-type subunits.  相似文献   

17.
试验以32份转BcWRKY1转录因子基因的玉米株系为材料,针对不同受体材料筛选出耐盐性鉴定浓度,通过苗情观察和生理生化指标对转基因株系进行耐盐性鉴定,建立转基因玉米苗期耐盐性鉴定的方法,同时筛选耐盐性强的玉米新种质,为玉米抗逆性育种提供种质资源。结果表明,耐盐性筛选及鉴定的NaCl适宜浓度为300mmol/L。依据苗情观察评价方法,23份转基因材料耐盐性比受体对照提高了一个级别;依据苗期生理生化指标变化情况,建立了转基因后代株系耐盐性比对照提高程度的评定方法。32份试材中耐盐性比对照提高3级的株系有3份。  相似文献   

18.
赤霉素的生物合成是多种酶促反应的过程,与植物植株发育、逆境响应密切相关。为分析芝麻基因组中赤霉素合成相关基因的分布、结构和活性特征,本研究以芝麻基因组序列和不同组织转录组为对象,通过生物信息学方法,从中共鉴定出32个赤霉素合成相关基因,分属7个不同的基因家族,分布在除5号染色体外芝麻所有的染色体上。不同基因家族蛋白质肽链长度存在较大差异,其中CPS家族的蛋白质序列最长,平均包含776个氨基酸残基;KAO家族蛋白序列长度的变异最大,在401-834个氨基酸之间。所有芝麻赤霉素合成相关基因编码的蛋白质预测为亲水性蛋白。与拟南芥、水稻、大豆、葡萄、高粱、番茄等物种相比,芝麻中赤霉素合成相关基因数目处于中等水平,但CPS家族中芝麻的基因数目明显多于其他物种,进化分析表明,在分析的7个物种中,芝麻与番茄具有较近的进化关系。在不同组织中,7个相关基因家族表达模式不同。KS家族基因在种子、茎尖和叶片中表达相对较高;CPS家族基因在心皮和种子中活性较强,但在茎尖和叶片中几乎没有表达;KAO和KO家族基因在不同组织中整体上具有相对较高的活性,而KS、GA3ox家族的基因在不同组织中整体表达量较低。就不同组织而言,种子中的GA合成相关基因活性整体较高;而在根尖、茎尖、叶片等与芝麻植株形态建成密切相关的3个组织中,这些基因表达以根尖较突出、其次为茎尖,在叶片中的活性整体较低。本研究为解析芝麻赤霉素合成相关基因的结构特征及其在不同组织中的作用特点提供了基因信息和理论参考。   相似文献   

19.
根据生物信息学分析,同源性克隆分离玉米DCL1候选基因,鉴定该基因组织与逆境响应等表达特征,并分析其自然等位变异。结果表明,目标候选基因全长7 408 bp,与拟南芥和水稻DCL1基因氨基酸序列高度保守,相似度分别为91%和77%。mRNA定量PCR分析表明,该基因在幼叶和吐丝期雌穗中表达丰度分别是幼茎的75.35倍和16.21倍;高盐、脱水、ABA、低氮、低磷胁迫处理条件下,幼苗中高盐和ABA处理呈下调表达,低氮和低磷处理呈显著上调表达,脱水处理无显著变化。核苷酸与氨基酸序列的保守性、组织与逆境响应差异表达特征均与拟南芥和水稻等相似。87份玉米自交系10×全基因重测序数据分析结果表明,该基因遗传变异丰富,共83个位点存在自然变异,但外显子区域和主要的功能结构域序列相对保守,约2/3的自然变异集中在内含子区域,外显子区域的27个自然变异位点只有8个位点在16个材料存在氨基酸差异。  相似文献   

20.
Sets of triticale (X Triticosecale Wittmack) lines derived from the cv. Presto with HMW glutenin allele Glu-D1d (subunits 5+10) translocated from bread wheat (Triticum aestivum L.) chromosome 1D to chromosome 1R were evaluated for agronomic and grain quality characteristics in 2002–2005. Two different translocation types were used: (a) single translocation 1R.1D5+10-2 where the long arm of 1R carries the wheat segment from 1DL with the Glu-D1d replacing a secalin locus Sec-3, (b) double translocation Valdy where the long arm of 1R has the translocation 1R.1D5+10-2 and the short arm has a segment from 1DS carrying wheat loci Gli-D1 and Glu-D3. The presence of Glu-D1d was determined by polyacrylamide gel electrophoresis (PAGE-ISTA) and DNA markers. The tested lines of triticale were compared with the check triticale cv. Presto and with wheat cultivars of different bread making quality (E-C quality classes). Single translocation 1R.1D5+10-2 reduced grain yield by 16% and Valdy translocation by 24% as compared with cv. Presto. The Valdy translocation had substantially shortened spike length and reduced specific weight in comparison with check cv. Presto. Wet gluten content (according to the Perten method) was 12% in both translocation types, 8% in check Presto and on average 24% in wheat. Translocations increased the Zeleny sedimentation value (Valdy — 27 ml, 1R.1D5+10-2 – 25 ml, cv. Presto — 23 ml). Triticale had a very low Hagberg falling number (FN) of 62–70 s without significant differences, while wheat had on average 301 s. The translocations did not significantly increase loaf volume; however, they improved loaf shape (height/width ratio): Valdy — 0.61, 1R.1D5+10-2 – 0.56, cv. Presto 0.44, wheat on average 0.70. The dough was non-sticky in Valdy, slightly sticky in 1R.1D5+10-2 and sticky in cv. Presto. Problems with a low FN for improving bread making quality of triticale are discussed. Higher bread making quality can be influenced by appropriate combination with donors of low α-amylase activity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号