[学术文献] Differential Stem Proteomics and Metabolomics Profiles for Four Wheat Cultivars in Response to the Insect Pest Wheat Stem Sawfly 进入全文
Common wheat (Triticum aestivum L.) is a global staple crop, and insect pests can impact grain yield. The wheat stem sawfly (Cephus cinctus, WSS) is a major wheat pest, and while partial resistance has been deployed by breeding for a solid-stem trait, this trait is affected by environment. Here, a proteomics and metabolomics study was performed on four wheat cultivars to characterize a molecular response to WSS infestation. The cultivars Hatcher (hollow-stem partially tolerant), Conan (semisolid-stem-resistant), and Denali and Reeder (hollow-stem-susceptible) were infested with WSS, and changes in stem proteins and metabolites were characterized using liquid chromatography–mass spectrometry. The proteome was characterized as 1830 proteins that included five major biological processes, including metabolic processes and response to stimuli, and the metabolome (1823 metabolites) spanned eight chemical superclasses, including alkaloids, benzenoids, and lipids. All four varieties had a molecular response to WSS following infestation. Hatcher had the most distinct changes, whereby 62 proteins and 29 metabolites varied in metabolic pathways involving enzymatic detoxification, proteinase inhibition, and antiherbivory compound production via benzoxazinoids, neolignans, and phenolics. Taken together, these data demonstrate variation in the wheat stem molecular response to WSS infestation and support breeding for molecular resistance in hollow-stem cultivars.
[学术文献] Meta-Analysis of the QTLome of Fusarium Head Blight Resistance in Bread Wheat: Refining the Current Puzzle 进入全文
Background: Fusarium Head Blight (FHB) is a worldwide devastating disease of bread wheat (Triticum aestivum L.). Genetic resistance is the most effective way to control FHB and many QTL related to this trait have been mapped on the wheat genetic map. This information, however, must be refined to be more efficiently used in breeding programs and for the advance of the basic research. The objective of the present study was to in-depth analyze the QTLome of FHB resistance in bread wheat, further integrating genetic, genomic, and transcriptomic data, aiming to find candidate genes.Methods: An exhaustive bibliographic review on 76 scientific papers was carried out collecting information about QTL related to FHB resistance mapped on bread wheat. A dense genetic consensus map with 572,862 loci was generated for QTL projection. Meta-analysis could be performed on 323 QTL. Candidate gene mining was carried out within the most refined loci, containing genes that were cross-validated with publicly available transcriptional expression data of wheat under Fusarium infection. Most highlighted genes were investigated for protein evidence.Results: A total of 556 QTL were found in the literature, distributed on all sub-genomes and chromosomes of wheat. Meta-analysis generated 65 meta-QTL, and this refinement allows one to find markers more tightly linked to these regions. Candidate gene mining within the most refined meta-QTL, meta-QTL 1/chr. 3B, harvested 324 genes and transcriptional data cross-validated 10 of these genes, as responsive to FHB. One is of these genes encodes a Glycosiltransferase and the other encodes for a Cytochrome P450, and these such proteins have already been verified as being responsible for FHB resistance, but the remaining eight genes still have to be further studied, as promising loci for breeding.Results: A total of 556 QTL were found in the literature, distributed on all sub-genomes and chromosomes of wheat. Meta-analysis generated 65 meta-QTL, and this refinement allows one to find markers more tightly linked to these regions. Candidate gene mining within the most refined meta-QTL, meta-QTL 1/chr. 3B, harvested 324 genes and transcriptional data cross-validated 10 of these genes, as responsive to FHB. One is of these genes encodes a Glycosiltransferase and the other encodes for a Cytochrome P450, and these such proteins have already been verified as being responsible for FHB resistance, but the remaining eight genes still have to be further studied, as promising loci for breeding.
[前沿资讯] Identification of candidate chromosome region of Sbwm1 for Soil-borne wheat mosaic virus resistance in wheat 进入全文
土传小麦花叶病毒（SBWMV）是一种严重的病毒性病害，在世界范围内严重影响小麦的产量。种植抗病品种是减少SBWMV危害的唯一可行策略。为精细定位抗性基因Sbwm1，采用90 K单核苷酸多态性分析技术对205份小麦品种进行基因分型。关联分析在12个小麦基因中鉴定出35个单核苷酸多态性，在Sbwm1区鉴定出一个基因间单核苷酸多态性，与SBWMV抗性有显著相关性。将这些SNPs转化为Kompetitive等位基因特异性多聚酶分析（KASP），并在两个抗病品种Wesley杂交产生的重组自交系（RIL）群体中进行分析。连锁分析表明，该基因在两个群体中分别以5.1 cM和3.4 cM的间隔定位在5D染色体上。两种群体的两个侧翼标记将基因分隔为一个620 kb的区域，其中注释了19个基因。比较分析发现Ae中有一个660 kb的合成区，有18个带注释的基因和1号染色体在一个同位区。候选区域包括几个与抗病相关的基因，我们确定了一个类似于PTI1的酪氨酸蛋白激酶1基因作为Sbwm1的假定候选基因。Sbwm1的两个侧翼SNPs能有效地分离出159份小麦新种质中的抗病和感病品系。本研究结果为SBWM1的克隆、功能鉴定和标记辅助选择奠定了坚实的基础。
[学术文献] Comparative transcriptome analysis of two common wheat varieties induced by 7Li-ion beam irradiation reveals mutation hotspot regions and associated pathways 进入全文
Heavy-ion beam irradiation is an effective approach for mutation breeding. Understanding the damage effects and molecular variation induced by mutagenesis is of great significance for improving mutation breeding efficiency. The molecular changes induced by 7Li-ion beam irradiation in wheat have been scarcely reported. In this study, we compared the biological damage effects of different doses of 7Li-ion beam irradiation on the M1 seedlings of two wheat varieties with different γ irradiation sensitivities, Jing411 and Heyou1, and found that doses of 25, 50, 75 and 100 Gy significantly decreased the germination rate and seedling height. Moreover, transcriptome sequencing of three biological replicates of each irradiated sample and unirradiated control revealed that more single-nucleotide variants (SNVs) than small insertions and deletions (indels) were induced by various doses of 7Li-ion beam irradiation in both varieties. Substantially elevated frequencies of mutations relative to gene density were observed on 0–10 Mb of chromosome 1A, 80–90 Mb of chromosome 1B, 720–730 Mb of chromosome 2B, 280–290 Mb of chromosome 3B, 580–590 Mb of chromosome 3D, and 150–160 Mb of chromosome 5D, indicating that mutation hotspots existed in these regions. In addition, KEGG enrichment analysis of differentially expressed genes (DEGs) between control and irradiated wheat revealed pathways significantly enriched in both Jing411 and Heyou1, including “Phenylpropanoid biosynthesis”, “Phenylalanine metabolism” and “Photosynthesis-antenna proteins”. These pathways may play key roles in the response to 7Li-ion beam irradiation. The analysis of genes commonly upregulated under various doses of irradiation indicated that genes involved in antioxidant processes are active in the response to 7Li-ion beam irradiation. This transcriptome dataset provides a valuable public information platform for investigating the transcriptome sequence variation induced by 7Li-ion beam-induced mutagenesis and offers a basis for crop mutation breeding.
[学术文献] Chemical composition and selected quality characteristics of new types of precooked wheat and spelt pasta products 进入全文
New types of precooked pasta products have been developed based on refined and wholegrain wheat and spelt flours. The resulting dry pasta was then assessed for chemical composition, including amino acids composition, phenolics content, as well as antioxidant activity. The precooked pasta quality was also evaluated for starch gelatinization degree, physical properties, hardness, color profile of dry and hydrated pasta, and sensory characteristics. We found that the application of the extrusion-cooking technique for wheat and spelt pasta processing allows to achieve instant products with good nutritional characteristics and high degree of gelatinization, as well as attractive quality and sensory profiles. Microstructure showed compact and dense internal structure with visible bran particles if wholegrain flours were used. Wholegrain wheat and wholegrain spelt precooked pasta were characterized by better nutritional composition and greater antioxidant potential, but lower firmness and increased adhesiveness when compared with refined flours.
[学术文献] Nutritional quality and health risks of wheat grains from organic and conventional cropping systems 进入全文
The influence of cropping systems on nutrition and food safety is controversial. This study aimed to evaluate the effects of an organic cropping system (OCS) on wheat nutrition and food safety at the molecular level by using a comprehensive research method. Nutrient deviation in samples from an OCS and a conventional cropping system (CCS) were detected, and 58 biomarkers were selected through multivariate statistical analysis and were further qualitatively and quantitatively analyzed. The health risk of heavy metal(loid)s (HMs) for different populations was assessed based on the estimated average daily dose and recommended ingestion reference dose, which indicated that populations ingesting grains from OCSs had higher non-carcinogenic and carcinogenic risks. Additionally, HMs posed greater non-carcinogenic risks to children under five years old and greater carcinogenic risks to adults. This study highlights the need to consider the potential risk from HMs and nutritive ingredient differences in organic food.