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[前沿资讯 ] Nitrogen Foliage Application at Anthesis Improves Grain Yield and Quality of Wheat in a Genotype-Dependent Manner 进入全文
MDPI
Crop quality tends to decrease with an increasing grain yield. Nitrogen is an important nutrient and moderate nitrogen foliage application (NFA) can significantly improve the wheat yield and quality. The objective of this study was to investigate the effect of NFA on the grain yield and quality of wheat and its genotype-dependent variation. Eighteen wheat cultivars were used, and two NFA levels (N1 and N2; 10.70 and 21.40 kg N ha−1 two day−1, respectively) were applied. Significant genotypic differences in the yield and quality were observed among the 18 varieties, and their responses to NFA differed. For nine varieties in the experiment, N1 increased the grain yield, but N2 did not. In contrast, high concentrations of NFA had no effect on the grain yield in the other nine varieties. The protein content and composition and trace element (Fe, Zn, etc.) are all nutrient elements that notably affect the wheat grain quality and yield. NFA significantly increased the grain prolamin and glutelin concentrations in the grains, thereby increasing the total protein concentration. The prolamin, glutelin, and total protein concentrations in the grains of the lower-protein cultivars were more sensitive to NFA than those of the higher-protein cultivars. In addition, NFA significantly decreased the amylose concentration in the grains. By affecting the prolamin, glutelin, and amylose concentrations in the grains, NFA significantly increased the development and stability times of the corresponding wheat flour dough, thereby improving the dough quality. Moreover, NFA reduced the molar ratio of phytic acid to Fe and Zn, increasing the bioavailability of trace elements. The judicious application of nitrogen fertilizer resulted in the synergistic improvement in the yield and quality.
[前沿资讯 ] Wheat stripe rust resistance locus YR63 is a hot spot for evolution of defence genes – a pangenome discovery 进入全文
BMC Plant Biology
Background Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), poses a threat to global wheat production. Deployment of widely effective resistance genes underpins management of this ongoing threat. This study focused on the mapping of stripe rust resistance gene YR63 from a Portuguese hexaploid wheat landrace AUS27955 of the Watkins Collection. Results YR63 exhibits resistance to a broad spectrum of Pst races from Australia, Africa, Asia, Europe, Middle East and South America. It was mapped to the short arm of chromosome 7B, between two single nucleotide polymorphic (SNP) markers sunCS_YR63 and sunCS_67, positioned at 0.8 and 3.7 Mb, respectively, in the Chinese Spring genome assembly v2.1. We characterised YR63 locus using an integrated approach engaging targeted genotyping-by-sequencing (tGBS), mutagenesis, resistance gene enrichment and sequencing (MutRenSeq), RNA sequencing (RNASeq) and comparative genomic analysis with tetraploid (Zavitan and Svevo) and hexaploid (Chinese Spring) wheat genome references and 10+ hexaploid wheat genomes. YR63 is positioned at a hot spot enriched with multiple nucleotide-binding and leucine rich repeat (NLR) and kinase domain encoding genes, known widely for defence against pests and diseases in plants and animals. Detection of YR63 within these gene clusters is not possible through short-read sequencing due to high homology between members. However, using the sequence of a NLR member we were successful in detecting a closely linked SNP marker for YR63 and validated on a panel of Australian bread wheat, durum and triticale cultivars. Conclusions This study highlights YR63 as a valuable source for resistance against Pst in Australia and elsewhere. The closely linked SNP marker will facilitate rapid introgression of YR63 into elite cultivars through marker-assisted selection. The bottleneck of this study reinforces the necessity for a long-read sequencing such as PacBio or Oxford Nanopore based techniques for accurate detection of the underlying resistance gene when it is part of a large gene cluster.
[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.
[相关专利 ] 一种面包面条兼用型红皮高硬度强筋小麦的育种方法 进入全文
国家知识产权局
本发明公开了一种面包面条兼用型红皮高硬度强筋小麦育种方法，以携带高硬度基因(Pin)、优质高分子量谷蛋白亚基(HMW-GS)或Wx基因部分缺失材料为亲本,创制长江中下游麦区当前主栽红皮小麦品种背景的携不同优质基因材料，并进一步杂交、回交或复交；综合利用高通量分子标记检测，明确红皮强筋小麦品质评价指标和标准，高效全面品质跟踪测试，培育聚合高硬度基因(Pin)，优质高分子量谷蛋白亚基(HMW-GS)和Wx基因部分缺失3个优质分子模块基因材料，定向设计改良红皮高硬度强筋小麦品质；同时加强产量性状和综合农艺鉴定，实现红皮强筋小麦产量和质量协同改良。本方法极大提高了面包面条兼用型红皮高硬度强筋小麦育种效率和精确性。
[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.
