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[学术文献 ] Efficiency of indirect selection for fusarium head blight resistance and mycotoxin accumulation in winter wheat (Triticum aestivum L.) 进入全文
WILEY online Library
Fusarium head blight (FHB) is one of the most devastating diseases of wheat and can lead to significant yield losses as well as a contamination of the crop with mycotoxins that are a major concern in cereal-based food and feed products. The aims of this study were thus to investigate the relationship between resistance against multiple Fusarium species and to assess the potential of an indirect phenotypic and genomic selection for the resistance against the accumulation of several mycotoxins in wheat. Strong phenotypic and genetic correlations between the mycotoxin contents, FHB severity and FHB-associated traits were observed, irrespective of if traits were assessed in trials inoculated with a DON or HT-2/T-2 producing Fusarium species. A multi-stage phenotypic or genomic selection with low anther retention being used for an indirect selection among early generation selection candidates, followed by an evaluation of the pre-selected set in disease nurseries, and lastly by assessing the mycotoxin content of the most promising genotypes is suggested as a suitable strategy to breed for wheat cultivars with reduced risk of mycotoxin accumulation.
[学术文献 ] Genetic mapping of the wheat leaf rust resistance gene Lr2a and its importance in Canadian wheat cultivars 进入全文
SPRINGER LINK
Incorporating effective leaf rust resistance (Lr) genes into high-yielding wheat cultivars has been an efficient method of disease control. One of the most widely used genes in Canada is the multi-allelic resistance gene Lr2, with alleles Lr2a, Lr2b, Lr2c, and Lr2d. The Lr2a allele confers complete resistance to a large portion of the Puccinia triticina (Pt) population in Canada. In this study, Lr2a was genetically mapped in two doubled haploid populations developed from the crosses Superb/BW278 and Superb/86ISMN 2137, and an F2 population developed from the cross Chinese Spring/RL6016. Seedlings were tested with the Lr2a avirulent Pt races 74-2 MGBJ (Superb/BW278) and 12-3 MBDS (Superb/86ISMN 2137 and Chinese Spring/RL6016) in greenhouse assays and were genotyped with 90K wheat Infinium SNP and kompetitive allele-specific PCR (KASP) markers. Lr2a was mapped to a collinear position on chromosome arm 2DS in all three populations, within a 1.00 cM genetic interval between KASP markers kwm1620 and kwm1623. This corresponded to a 305 kb genomic region of chromosome 2D in Chinese Spring RefSeq v2.1. The KASP marker kwh740 was predictive of Lr2a in all mapping populations. A panel of 260 wheats were tested with three Pt isolates, which revealed that Lr2a is common in Canadian wheats. The KASP markers kwh740 and kwm1584 were highly associated with resistance at the Lr2 locus, while kwm1622 was slightly less correlated. Genetic mapping of the leaf rust resistance gene Lr2a and DNA markers developed here will facilitate its use in wheat breeding programs.
[学术文献 ] Comparison of mixing and non-linear viscoelastic properties of carob germ glutelins and wheat glutenin 进入全文
ScienceDirect
Carob germ glutelins were compared to wheat glutenin from a rheological standpoint to provide a basis for the possible use of carob germ glutelins as a non-gluten protein in gluten-free dough systems. Molecular weight distributions, mixing and non-linear viscoelastic properties of carob germ glutelins and wheat glutenin were compared, while the impact of mixing on non-linear rheological properties of these protein fractions were evaluated over short (4-min) and long (35-min) mixing times. Development time was 13 min for carob germ glutelins, while reaching 500 BU consistency took 34 min for wheat glutenin, suggesting faster hydration for carob germ glutelins due to their relatively lower molecular weight distribution and more hydrophilic nature. Phase angle values revealed similar linear viscoelastic properties for both proteins after 4-min and 35-min mixing. However, Large Amplitude Oscillatory Shear (LAOS) tests indicated type I non-linear behavior for carob germ glutelins and type III non-linear behavior for wheat glutenin after 35-min mixing at which both proteins had similar consistencies, pointing out to weaker stability for carob germ glutelins when exposed to large deformations. Higher degree of strain stiffening and shear thinning behaviors were found for carob germ glutelins in the non-linear region. Increasing mixing time caused a decrease in the strain stiffening behavior of wheat glutenin under large strain-high frequency deformations, while strain stiffening behavior of carob germ glutelins remained similar. Comparing the mixing and LAOS properties of carob germ glutelins to those of wheat glutenin unraveled the processing needs of dough systems where carob germ glutelins could be used as a non-gluten protein to produce alternative gluten-free baked products with improved quality.
[学术文献 ] Wheat DOF transcription factors TaSAD and WPBF regulate glutenin gene expression in cooperation with SPA 进入全文
PubMed Central
Grain storage proteins (GSPs) quantity and composition determine the end-use value of wheat flour. GSPs consists of low-molecular-weight glutenins (LMW-GS), high-molecular-weight glutenins (HMW-GS) and gliadins. GSP gene expression is controlled by a complex network of DNA-protein and protein-protein interactions, which coordinate the tissue-specific protein expression during grain development. The regulatory network has been most extensively studied in barley, particularly the two transcription factors (TFs) of the DNA binding with One Finger (DOF) family, barley Prolamin-box Binding Factor (BPBF) and Scutellum and Aleurone-expressed DOF (SAD). They activate hordein synthesis by binding to the Prolamin box, a motif in the hordein promoter. The BPBF ortholog previously identified in wheat, WPBF, has a transcriptional activity in expression of some GSP genes. Here, the wheat ortholog of SAD, named TaSAD, was identified. The binding of TaSAD to GSP gene promoter sequences in vitro and its transcriptional activity in vivo were investigated. In electrophoretic mobility shift assays, recombinant TaSAD and WPBF proteins bound to cis-motifs like those located on HMW-GS and LMW-GS gene promoters known to bind DOF TFs. We showed by transient expression assays in wheat endosperms that TaSAD and WPBF activate GSP gene expression. Moreover, co-bombardment of Storage Protein Activator (SPA) with WPBF or TaSAD had an additive effect on the expression of GSP genes, possibly through conserved cooperative protein-protein interactions.
[学术文献 ] Evaluating Total Phenolic Content, Antioxidant Activity, High Molecular Weight Glutenin Subunits (HMW-GS), and Grain Yield Parameters of Cultivated Wheat and Hybrids 进入全文
SpringerLink
This study was conducted to assess the high molecular weight glutenin subunits (HMW-GS), yield, total phenolic content (TPC), and antioxidant capacity using five assays: free radical scavenging (DPPH and ABTS), reducing power (CUPRAC and FRAP), and phosphomolybdenum. Wheat species, old cultivar, landrace, and hybrid wheat genotypes were compared with adaptive modern bread and durum wheat cultivars. Under rainfed conditions, high grain yield was particularly obtained from T. turanicum, T. polonicum, and T. compactum wheat species, as T. spelta, T. compactum, T. turanicum, T. turgidum, and T. polonicum were better performed to grain yield under irrigated conditions. In the study, the wheat genotypes, T. petropavlovskyi, T. spelta, T. sphaerococcum, T. compactum, Yektay 406, Ak 702, Köse 220/39, and wheat hybrids were found to have the HMW-GS 2 + 12 in Glu-D1 in relation to low quality. The Yellowstone wheat cultivar carried high-quality alleles together for 1 in Glu-A1 and 5 + 10 in Glu-D1. The study exhibited that T. monococcum (einkorn), T. spelta (spelt), T. dicoccum (emmer), and Yektay 406 (old cultivar) for better antioxidant capacity were displayed together in the same cluster of the dendrogram constructed by DPPH, ABTS, CUPRAC, FRAP, and phosphomolybdenum assay results. In addition, significant correlations were observed between TPC, ABTS, CUPRAC, FRAP, and phosphomolybdenum. The study suggested that ancient wheat species superior to the investigated characteristics had antioxidants beneficial for healthy nutrition and may also be used in the improvement of cultivars with high yield and quality.
[学术文献 ] The conformation of glutenin polymers in wheat grain: some genetic and environmental factors associated with this important characteristic 进入全文
OXFORD ACADEMlC
In a previous study we used asymmetric-flow field-flow fractionation to determine the polymer mass (Mw), gyration radius (Rw) and the polydispersity index of glutenin polymers (GPs) in wheat (Triticum aestivum). Here, using the same multi-location trials (4 years, 11 locations, and 192 cultivars), we report the factors that are associated with the conformation (Conf) of the polymers, which is the slope of Log(Rw) versus a function of Log(Mw). We found that Conf varied between 0.285 and 0.740, it had low broad-sense heritability (H2=16.8), and it was significantly influenced by the temperature occurring over the last month of grain filling. Higher temperatures were found to increase Rw and the compactness and sphericity of GPs. Alleles for both high- and low-molecular-weight glutenin subunits had a significant influence on the Conf value. Assuming a Gaussian distribution for Mw, the number of polymers present in wheat grains was computed for different kernel weights and protein concentrations, and it was found to exceed 1012 GPs per grain. Using atomic force microscopy and cryo-TEM, images of GPs were obtained for the first time. Under higher average temperature, GPs became larger and more spherical and consequently less prone to rapid hydrolysis. We propose some orientations that could be aimed at potentially reducing the impact of numerous GPs on people suffering from non-celiac gluten sensitivity.
