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Nucleotide-binding leucine-rich repeat (NLR) disease resistance genes typically confer resistance against races of a single pathogen. Here, we report that Yr87/Lr85, an NLR gene from Aegilops sharonensis and Aegilops longissima, confers resistance against both P. striiformis tritici (Pst) and Puccinia triticina (Pt) that cause stripe and leaf rust, respectively. Yr87/Lr85 confers resistance against Pst and Pt in wheat introgression as well as transgenic lines. Comparative analysis of Yr87/Lr85 and the cloned Triticeae NLR disease resistance genes shows that Yr87/Lr85 contains two distinct LRR domains and that the gene is only found in Ae. sharonensis and Ae. longissima. Allele mining and phylogenetic analysis indicate multiple events of Yr87/Lr85 gene flow between the two species and presence/absence variation explaining the majority of resistance to wheat leaf rust in both species. The confinement of Yr87/Lr85 to Ae. sharonensis and Ae. longissima and the resistance in wheat against Pst and Pt highlight the potential of these species as valuable sources of disease resistance genes for wheat improvement., Competing Interests: Competing interests The authors declare the following competing interests: D.S., R.A., R.K, E.M., A.M-D., and A.S. are inventors on the US patent application 63/250,413 filed by Ramot (Tel Aviv University) and relating to the use of Yr87/Lr85 for leaf and stripe rust resistance in transgenic wheat. All other authors claim no competing interests., (© 2024. The Author(s).)

Background: Developing wheat cultivars with durable resistance to powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is crucial for sustainable agriculture. The wheat genotype MYC exhibited high resistance to the Bgt isolate E09 at the seedling stage. Genetic analysis identified a recessive gene, temporarily named PmMYC, responsible for this resistance. Understanding the molecular mechanisms underlying this resistance is essential for advancing breeding programs., Results: Bulked Segregant RNA-Seq revealed numerous alternative splicing events generated following Bgt infection, suggesting powdery mildew may disrupt alternative splicing and affect immune responses. Gene Ontology (GO) analysis indicated significant enrichment of differentially expressed genes in "response to stimuli" and "immune system processes", implying their roles in disease defense. BSR-Seq analysis identified two high-confidence candidate regions for PmMYC on chromosome 2B, spanning 40,451,950 - 102,426,703 bp and 421,707,046-449,840,516 bp. Within these intervals, 740 genes were identified, with nonsynonymous mutations in 46 genes in the parents and bulks. Real-time PCR showed distinct expression profiles in four genes in resistant MYC compared to susceptible Yannong 21. KEGG and COG analyses of differentially expressed genes in candidate intervals revealed enrichment in immune processes related to plant-pathogen interactions, confirming that PmMYC initiated a broad immune response to prevent Bgt invasion., Conclusion: The study identified key genetic intervals and genes involved in the resistance of wheat genotype MYC to Bgt. The identified genes, particularly those with altered expression profiles, could serve as valuable targets for breeding programs aimed at developing wheat cultivars with durable resistance to powdery mildew. These findings enhanced our understanding of plant-pathogen interactions and provided a foundation for future genetic and functional studies., Competing Interests: Declarations Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Wheat and buckwheat allergies are common food allergies that significantly impact patients' quality of life and health. Wheat allergy encompasses various forms, including wheat food allergy, exercise-induced allergic reactions (WDEIA), baker's occupational asthma/allergy, and contact urticaria. IgE-mediated allergic reactions involve sensitization to stable wheat allergens such as ω-5 gliadin and gluten. Although buckwheat allergy is less common, it is gaining attention in certain regions. Allergen component diagnostic technologies, by detecting specific allergen components [e.g., ω-5 gliadin, gliadins (α, β, γ), and Tri a 14], offer precise allergen source identification, aiding in the optimization of diagnosis and management processes. Oral challenge tests are considered the gold standard for diagnosing wheat allergy, and combining skin prick tests with specific IgE measurements can enhance diagnostic accuracy. While avoidance of allergens remains the primary management strategy, research into immunotherapy is ongoing. Future research should focus on a deeper understanding of the structural and immunological characteristics of wheat and buckwheat allergens to develop more accurate diagnostic tools and treatment methods, thereby improving allergy management and patient quality of life. This article provides a detailed interpretation of the Molecular Allergology User's Guide 2.0 (MAUG 2.0) published by the European Academy of Allergy and Clinical Immunology (EAACI) and recent research advances on wheat and buckwheat allergies, highlighting the crucial role of allergen component diagnostics in optimizing food allergy diagnosis and treatment processes, supporting clinicians in accurately identifying common allergens and their cross-reactivity, and formulating more personalized treatment plans for patients.

Wheat (Triticum aestivum L.) is a globally staple crop vulnerable to various fungal diseases, significantly impacting its yield. Plant cell surface receptors play a crucial role in recognizing pathogen-associated molecular patterns (PAMPs) and activating PAMP-triggered immunity, boosting resistance against a wide range of plant diseases. Although the role of plant chitin receptor CERK1 in immune recognition and defense has been established in Arabidopsis and rice, its function and potential agricultural applications in enhancing resistance to crop diseases remain largely unexplored. Here, we identify and characterize TaCERK1 in Triticeae crop wheat, uncovering its involvement in chitin recognition, immune regulation, and resistance to fungal diseases. By a comparative analysis of CERK1 homologs in Arabidopsis and monocot crops, we demonstrate that AtCERK1 in Arabidopsis elicits the most robust immune response. Moreover, we show that overexpressing TaCERK1 and AtCERK1 in wheat confers resistance to multiple fungal diseases, including Fusarium head blight, stripe rust, and powdery mildew. Notably, transgenic wheat lines with moderately expressed AtCERK1 display superior disease resistance and heightened immune responses without adversely affecting growth and yield, compared to TaCERK1 overexpression transgenics. Our findings highlight the significance of plant chitin receptors across diverse plant species and suggest potential strategies for bolstering crop resistance against broad-spectrum diseases in agricultural production through the utilization of plant immune receptors., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Puccinia striiformis f. sp. tritici (Pst) has a wide range and serious damage, which severely threatens global wheat production. In this study, we focused on an effector protein Pst3180.3, which was induced to be highly expressed during the Pst infection stage. The N-terminal 19 amino acid of Pst3180.3 was verified to function as a signal peptide and transferred to cytoplasm and nucleus of wheat following Pst infection. Transient overexpression of Pst3180.3 in Nicotiana benthamiana inhibited programmed cell death triggered via BAX. The instantaneous silencing of Pst3180.3 by BSMV- HIGS significantly reduced the number of uredinia and increased accumulation of reactive oxygen species. Those results indicated that Pst3180.3 is an important pathogenic factor of Pst. Interaction of Pst3180.3 with a transcription factor TaMYB4L in host was confirmed through yeast two-hybrid, luciferase complementation, and co-immunoprecipitation. Virus-induced gene silencing of TaMYB4L weakened the resistance to Pst, indicated that TaMYB4L may be involved in the positive regulation of plant immunity. Dual-luciferase assays revealed that Pst3180.3 inhibited the transcriptional activity of TaMYB4L. Meanwhile, molecular docking analysis identified the key residue sites for the interaction and binding between Pst3180.3 and MYB4L. Those results demonstrated that Pst3180.3 binds to TaMYB4L and interacts to inhibit wheat resistance to Pst infection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: The bead-based epitope assay has been used to identify epitope-specific (es) antibodies and successfully used to diagnose clinical allergy to milk, egg, and peanut., Objective: We sought to identify es-IgE, es-IgG4, and es-IgG1 of wheat proteins and determine the optimal peptides to differentiate wheat-allergic from wheat-tolerant using the bead-based epitope assay., Methods: Children and adolescents who underwent an oral food challenge to confirm their wheat allergy status were enrolled. Seventy-nine peptides from α-/β-gliadin, γ-gliadin, ω-5-gliadin, and high- and low-molecular-weight glutenin were commercially synthesized and coupled to LumAvidin beads (Luminex Corporation, Austin, Tex). Machine learning methods were used to identify diagnostic epitopes, and performance was evaluated using the DeLong test., Results: The analysis included 122 children (83 wheat-allergic and 39 wheat-tolerant; 57.4% male). Machine learning coupled with simulations identified wheat es-IgE, but not es-IgG4 or es-IgG1, to be the most informative for diagnosing wheat allergy. Higher es-IgE binding intensity correlated with the severity of allergy phenotypes, with wheat anaphylaxis exhibiting the highest es-IgE binding intensity. In contrast, wheat-dependent exercise-induced anaphylaxis showed lower es-IgG1 binding intensity than did all the other groups. A set of 4 informative epitopes from ω-5-gliadin and γ-gliadin were the best predictors of wheat allergy, with an area under the curve of 0.908 (sensitivity, 83.4%; specificity, 88.4%), higher than the performance exhibited by wheat-specific IgE (area under the curve = 0.646; P < .001). The predictive ability of our model was confirmed in an external cohort of 71 patients (29 allergic, 42 nonallergic), with an area under the curve of 0.908 (sensitivity, 75.9%; specificity, 90.5%)., Conclusions: The wheat bead-based epitope assay demonstrated greater diagnostic accuracy compared with existing specific IgE tests for wheat allergy., Competing Interests: Disclosure statement This research project was supported by a grant from the Faculty of Medicine, Siriraj Hospital, Mahidol University (grant no. Internal Order [IO] R016232026) and by the David H. and Julia Koch Research Program in Food Allergy Research. Disclosure of potential conflict of interest: M. Suárez-Fariñas reports consultancy feeds from DBV Technologies. M. Suprun is currently an employee at Janssen Pharmaceutical. H. A. Sampson reports funding to his institution for grants from the National Institutes of Health/National Institute of Allergy and Infectious Diseases; has received consulting fees from DBV Technologies, N-Fold Therapeutics, LLC, and Siolta, Inc; and has received stock options from DBV Technologies and N-Fold Therapeutics, LLC. The rest of the authors declare that they have no relevant conflicts of interest., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Nucleotide-binding leucine-rich repeat (NLR) proteins contribute widely to plant immunity by regulating defense mechanisms through the elicitation of a hypersensitive response (HR). Here, we find that TaRACK1B (the receptor for activated C-kinase 1B) regulates wheat immune response against Chinese wheat mosaic virus (CWMV) infection. TaRACK1B recruits TaSGT1 and TaHSP90 to form the TaRACK1B-TaSGT1-TaHSP90 complex. This complex is essential for maintaining NLR proteins' stability (TaRGA5-like and TaRGH1A-like) in order to control HR activation and inhibit viral infection. However, the cysteine-rich protein encoded by CWMV can disrupt TaRACK1B-TaSGT1-TaHSP90 complex formation, leading to the reduction of NLR-protein stability and suppression of HR activation, thus promoting CWMV infection. Interestingly, the 7K protein of wheat yellow mosaic virus also interferes with this antiviral immunity. Our findings show a shared viral counter-defense strategy whereby two soil-borne viruses may disrupt the TaRACK1B-TaSGT1-TaHSP90 complex, suppressing NLR-protein-mediated broad-spectrum antiviral immunity and promoting viral infection in wheat., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The impact of a concentrate-rich (CR) diet on the gut microbiome and epithelium homeostasis is well documented. However, it has not been systematically studied whether and how host-microbial interaction contributes to the immune homeostasis in the rumen and colon of lambs fed alfalfa hay and wheat straw, alone or combined, in a CR diet. In all, 63 lambs (initial body weight, 16.69 ± 1.50 kg) were randomly allotted to three dietary groups, each consisting of three pens with seven lambs per pen. Over 14 weeks, the lambs were fed diets as follows: 60% concentrate supplemented with either 40% wheat straw (WG), 20% alfalfa hay combined with 20% wheat straw (MG), or 40% alfalfa hay (AG). The present findings showed that lambs in the AG group had greater ( P < 0.05) IgG and lower ( P = 0.067) tumor necrosis factor-alpha concentrations relative to those in the MG and WG groups. The 16S rRNA analysis highlighted that various bacterial phyla and genera in the rumen and colon preferentially degrade fiber and starch derived from alfalfa hay and wheat straw. The weighted gene co-expression network analysis revealed that the bacterial genera from the Firmicutes are broadly associated with genes involved in various signaling pathways, underscoring the potential role of Firmicutes as key drivers of host-microbial interactions under the present feeding conditions. These findings shed light on the fact that the rumen and colon immune homeostasis is distinctively influenced by diets of alfalfa hay, wheat straw, or their combination in a CR diet. Further studies should examine the prolonged effects of replacing wheat straw with alfalfa hay in a concentrate-rich diet formulated to provide equivalent neutral detergent fiber levels. This could reveal how various forage fibers influence host-microbial interactions and gut health.IMPORTANCEIn contemporary feedlots, a growing trend is to feed animals a concentrate-rich (CR) diet that could disrupt the synchronized interplay between microbes and host metabolism, leading to altered metabolic functions. Wheat straw and alfalfa hay have different levels of protein and neutral detergent fiber, each with varying rates of digestion. It is unclear how including alfalfa hay and wheat straw, alone or combined in a CR diet, influences the host-microbial consortia and immune homeostasis. Herein, we showed that rumen and colon showed differential immune responses to the alfalfa hay, wheat straw, or both. Bacterial genera preferentially degrade fiber and starch derived from alfalfa hay, wheat straw, or both. Bacterial genera from Firmicutes phylum play a pivotal role in driving the host-microbial interactions, as indicated by their extensive association with genes across various signaling pathways., Competing Interests: The authors declare no conflict of interest.

Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), one of the most economically destructive wheat foliar diseases. In this study, we explore the physiological and molecular changes elicited in two wheat cultivars with divergent responses (Taichung 29 = susceptible, and Shafir = resistant) upon infection by Z. tritici. Our aim is to uncover novel insights into the intricate mechanisms that govern wheat defense against Z. tritici infection. Our quantitative histopathological study showed that H2O2 accumulated in the resistant cultivar to a higher degree compared to the susceptible cultivar at the biotrophic and switching phase. Additionally, we combined qPCR with a targeted quantitative HPLC technique to evaluate the expression profiles of 13 defense-related genes and profile the polyphenolic compounds induced differentially in the STB susceptible and resistant cultivar. Our finding indicated that five out of 13 genes were strongly up-regulated in the resistant cultivar compared with that of the susceptible one at eight days post-inoculation (dpi), corresponding to the transition phase present in the infection process of Z. tritici. Finally, our targeted HPLC analysis demonstrated that the traced phenolic compounds were highly elevated in the susceptible cultivar infected by Z. tritici compared with that of the resistant cultivar. In conclusion, our comprehensive analysis unveils a robust defense response in the resistant wheat cultivar Shafir, characterized by heightened H2O2 accumulation, significant up-regulation of key defense-related genes during the transition phase, and a distinct profile of polyphenolic compounds, shedding light on the intricate mechanisms contributing to its resistance against Z. tritici, thereby providing valuable insights for the development of more resilient wheat varieties., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Mirzadi Gohari et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Zymoseptoria tritici is the most economically significant fungal pathogen of wheat in Europe. However, despite the importance of this pathogen, the molecular interactions between pathogen and host during infection are not well understood. Herein, we describe the use of two libraries of cloned Z. tritici effectors that were screened to identify effector candidates with putative pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI)-suppressing activity. The effectors from each library were transiently expressed in Nicotiana benthamiana, and expressing leaves were treated with bacterial or fungal PAMPs to assess the effectors' ability to suppress reactive oxygen species (ROS) production. From these screens, numerous effectors were identified with PTI-suppressing activity. In addition, some effectors were able to suppress cell death responses induced by other Z. tritici secreted proteins. We used structural prediction tools to predict the putative structures of all of the Z. tritici effectors and used these predictions to examine whether there was enrichment of specific structural signatures among the PTI-suppressing effectors. From among the libraries, multiple members of the killer protein-like 4 (KP4) and killer protein-like 6 (KP6) effector families were identified as PTI suppressors. This observation is intriguing, as these protein families were previously associated with antimicrobial activity rather than virulence or host manipulation. This data provides mechanistic insight into immune suppression by Z. tritici during infection and suggests that, similar to biotrophic pathogens, this fungus relies on a battery of secreted effectors to suppress host immunity during early phases of colonization., (© 2024 The Author(s). Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)

Hypersensitive response-programmed cell death (HR-PCD) regulated by Ca 2+ signal is considered the major regulator of resistance against Puccinia triticina (Pt.) infection in wheat. In this study, the bread wheat variety Thatcher and its near-isogenic line with the leaf rust resistance locus Lr26 were infected with the Pt. race 260 to obtain the compatible and incompatible combinations, respectively. The expression of translationally controlled tumor protein (TaTCTP) was upregulated upon infection with Pt., through a Ca 2+ -dependent mechanism in the incompatible combination. The knockdown of TaTCTP markedly increased the area of dying cell and the number of Pt. haustorial mother cells (HMCs) at the infection sites, whereas plants overexpressing the gene exhibited enhanced resistance. The interaction between TaTCTP and calcineurin B-like protein-interacting protein kinase 23 (TaCIPK23) was also investigated, and the interaction was found occurred in the endoplasmic reticulum. TaCIPK23 phosphorylated TaTCTP in vitro. The expression of a phospho-mimic TaTCTP mutant in Nicotiana benthamiana promoted HR-like cell death. Silencing TaCIPK23 or TaCIPK23/TaTCTP co-silencing resulted in the same results as silencing TaTCTP. This suggested that TaTCTP is a novel phosphorylation target of TaCIPK23, and both participate in the resistance of wheat to Pt. in the same pathway., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Higher levels of ergot ( Claviceps purpurea [Fr.] Tul.) were reported in North Dakota hard red spring wheat (HRSW) in 2018, leading to questions pertaining to management and cultivar resistance. To better understand pathogen and HRSW cultivar responses, greenhouse experiments were conducted from 2020 to 2021 to evaluate the aggressiveness of nine C. purpurea isolates and ergot resistance in 21 HRSW cultivars. Results from the aggressiveness assay indicated significant cultivar-by-isolate interactions for the total weight of sclerotia produced and ergot incidence. Mean data across all cultivars by isolate combinations suggested isolates CC-3 and IA-Tim were the most aggressive, and these were subsequently used in ergot resistance experiments. Results from ergot resistance screening indicated that none of the HRSW cultivars were immune to C. purpurea because all cultivars produced sclerotia. However, differences in ergot incidence, kernel incidence, aborted kernel incidence, total sclerotia weight, sclerotia length, and sclerotia width occurred among cultivars. Both 'ND-Frohberg' and 'TCG-Spitfire' had the lowest ergot incidence values and were among the lowest in total sclerotia weight. 'Waldron' and 'LCS-Trigger' had the highest ergot incidence and the highest total sclerotia weight. Given that most concerns with ergot occur postharvest, we suggest two categories to describe ergot resistance: host resistance (fate of inoculation for a stigma) and logistical resistance (size characteristics of a sclerotium that influence its ability to remain with a seed lot after harvest and cleaning). This research provides a strong foundation for our understanding of HRSW resistance to ergot that will influence variety decisions in ergot-prone areas in North Dakota., Competing Interests: The author(s) declare no conflict of interest.

We have previously shown the ability of transamidated gluten (spf) to modulate both innate and adaptive intestinal immunity elicited by wheat gliadin in HLA-DQ8 transgenic mice (DQ8 mice), a model of gluten sensitivity. Herein, we evaluated the influence of spf when administered intragastrically on the immune response to native gliadin in DQ8 mice. To address the issue, we analysed three regimens of antigen administration: before immunisation (pre-treatment), during immunisation (co-treatment) and through breast milk during the lactating phase (suckling treatment). Mice were immunised mucosally by intranasal delivery of digested wheat gliadin along with cholera toxin in multiple doses. After sacrifice, isolated spleen and mesenteric lymph node (MLN) cells were challenged in vitro and the cytokine profile of culture supernatants assessed by ELISA and multiparametric assay. We found that only pre-treatment with spf was effective in down-regulating the gliadin-specific IFN-γ response and only in spleen cells. Interestingly, spf pre-treatment also induced systemic IL-6, IL-17A and TNF-α. By contrast, we found that spf pre-treatment upregulated INF-γ in MLN but also significantly decreased IL-2. In conclusion, our data provide evidence that the preventive intragastric administration of transamidated gluten is able to interfere with the classical cytokine profile induced by gliadin via mucosal immunisation in a transgenic model expressing one of the HLA molecules associated with coeliac disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lesion mimic mutants (LMMs) refer to the spontaneous formation of disease-like spots on leaves without any obvious pathogen infection. The LMM genes can regulate plant immunity, thus promoting the defense of crops against pathogens. However, there is a lack of systematic understanding of the regulatory mechanism of LMMs in wheat. This study identified a wheat LMM TaCAT2, a homolog of the Arabidopsis CAT2. The prediction of the cis-regulatory element revealed that TaCAT2 was involved in the response of plants to various hormones and stresses. RT-qPCR analysis indicated that TaCAT2 was significantly up-regulated by NaCl, drought, and Fusarium graminearum infection. Fluorescence microscopy showed that the TaCAT2 was localized to the peroxisome. Overexpression of TaCAT2 enhanced plant resistance to Phytophthora infestation and F. graminearum by constitutionally activating SA and JA pathways. VIGS of TaCAT2 enhanced the sensitivity of wheat to F. graminearum. Further, TaCAT2 enhanced stress resistance by scavenging the excessive ROS and increasing the activities of antioxidative enzymes. This study lays the basis for the functional identification of TaCAT2 and its applicability in the disease resistance of wheat., Competing Interests: Declaration of competing interest We declare that we have no financial, personal and competing relationships with other people or organizations., (Copyright © 2024. Published by Elsevier B.V.)

Competing Interests: Disclosures The authors have no conflicts of interest to report.

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), reduces wheat yields and grain quality, thus posing a significant threat to global food security. Wild relatives of wheat serve as valuable resources for resistance to powdery mildew. Here, the powdery mildew resistance gene Pm6Sl is cloned from the wild wheat species Aegilops longissima. It encodes a nucleotide-binding leucine-rich repeat (NLR) protein featuring a CC-BED module formed by a zinc finger BED (Znf-BED) domain integrated into the coiled-coil (CC) domain. The function of Pm6Sl is validated via mutagenesis, gene silencing, and transgenic assays. In addition, we develop a resistant germplasm harbouring Pm6Sl in a very small segment with no linkage drag along with the diagnostic gene marker pm6sl-1 to facilitate Pm6Sl deployment in wheat breeding programs. The cloning of Pm6Sl, a resistance gene with BED-NLR architecture, will increase our understanding of the molecular mechanisms underlying BED-NLR-mediated resistance to various pathogens., (© 2024. The Author(s).)

Background: Septoria tritici blotch (STB) disease causes yield losses of up to 50 per cent in susceptible wheat cultivars and can reduce wheat production. In this study, genomic architecture for adult-plant STB resistance in a Septoria Association Mapping Panel (SAMP) having 181 accessions and genomic regions governing STB resistance in a South Asian wheat panel were looked for., Results: Field experiments during the period from 2019 to 2021 revealed those certain accessions, namely BGD52 (CHIR7/ANB//CHIR1), BGD54 (CHIR7/ANB//CHIR1), IND92 (WH 1218), IND8 (DBW 168), and IND75 (PBW 800), exhibited a high level of resistance. Genetic analysis revealed the presence of 21 stable quantitative trait nucleotides (QTNs) associated with resistance to STB (Septoria tritici blotch) on all wheat chromosomes, except for 2D, 3A, 3D, 4A, 4D, 5D, 6B, 6D, and 7A. These QTNs were predominantly located in chromosome regions previously identified as associated with STB resistance. Three Quantitative Trait Loci (QTNs) were found to have significant phenotypic effects in field evaluations. These QTNs are Q.STB.5A.1, Q.STB.5B.1, and Q.STB.5B.3. Furthermore, it is possible that the QTNs located on chromosomes 1A (Q.STB.1A.1), 2A (Q.STB&#95;DH.2A.1, Q.STB.2A.3), 2B (Q.STB.2B.4), 5A (Q.STB.5A.1, Q.STB.5A.2), and 7B (Q.STB.7B.2) could potentially be new genetic regions associated with resistance., Conclusion: Our findings demonstrate the importance of Asian bread wheat as a source of STB resistance alleles and novel stable QTNs for wheat breeding programs aiming to develop long-lasting and wide-ranging resistance to Zymoseptoria tritici in wheat cultivars., (© 2024. The Author(s).)

As a kind of obligate biotrophic fungus, Puccinia striiformis f. sp. tritici ( Pst ) secretes vast effectors via haustoria to host cells during the infection to inhibit host defense responses and promote fungal invasion. In this study, based on the completion of genome sequencing and haustorial transcriptome sequencing of Pst , we identified a Pst effector (Hasp155) that is significantly induced in the early stage of Pst infection to wheat. The 18 N-terminal amino acids of Hasp155 encoded a signal peptide with a secretory function. Transient expression of Hasp 155 in Nicotiana benthamiana inhibited Bax-induced cell death as well as chitin-triggered callose deposition and defense-related gene expression. Moreover, delivery of the Hasp155 protein into wheat cells via type three secretion systems (TTSS) led to reduced plant immunity to nonpathogenic bacteria and to the avirulent Pst race with decreased H 2 O 2 accumulation and promoted Pst development. Furthermore, transgenic overexpression of Hasp 155 significantly renders wheat resistance susceptible, resulting in a decreased defense response and increased Pst pathogenicity. Overall, these results indicate that Hasp155 is an important effector of Pst pathogenicity by suppressing plant immunity.

Wheat blast, caused by Pyricularia oryzae (syn. Magnaporthe oryzae ) pathotype Triticum (MoT), is a devastating disease that can result in up to 100% yield loss in affected fields. To find new resistance genes against wheat blast, we screened 199 accessions of Aegilops tauschii , the D genome progenitor of common wheat ( Triticum aestivum ), by seedling inoculation assays with Brazilian MoT isolate Br48 and found 14 resistant accessions. A synthetic hexaploid wheat line (Ldn/KU-2097) derived from a cross between the T. turgidum 'Langdon' (Ldn) and resistant A. tauschii accession KU-2097 exhibited resistance in seedlings and spikes against Br48. In an F 2 population derived from 'Chinese Spring' × Ldn/KU-2097, resistant and susceptible individuals segregated in a 3:1 ratio, suggesting that the resistance from KU-2097 is controlled by a single dominant gene. We designated this gene Rmg10 . Genetic mapping using an F 2:3 population from the same cross mapped the RMG10 locus to the short arm of chromosome 2D. Rmg10 was ineffective against Bangladesh isolates but effective against Brazilian isolates. Field tests in Bolivia showed increased spike resistance in a synthetic octaploid wheat line produced from a cross between common wheat cultivar 'Gladius' and KU-2097. These results suggest that Rmg10 would be beneficial in farmers' fields in South America., Competing Interests: The author(s) declare no conflict of interest.

Global wheat production amounted to >780 MMT during 2022-2023 whose market size are valued at >$128 billion. Wheat is highly susceptible to high-temperature stress (HTS) throughout the life cycle and its yield declines 5-7% with the rise in each degree of temperature. Previously, we reported an array of HTS-response markers from a resilient wheat cv. Unnat Halna and described their putative role in heat acclimation. To complement our previous results and identify the key determinants of thermotolerance, here we examined the cytoplasmic proteome of a sensitive cv. PBW343. The HTS-triggered metabolite reprograming highlighted how proteostasis defects influence the formation of an integrated stress-adaptive response. The proteomic analysis identified several promising HTS-responsive proteins, including a NACα18 protein, designated TaNACα18, whose role in thermotolerance remains unknown. Dual localization of TaNACα18 suggests its crucial functions in the cytoplasm and nucleus. The homodimerization of TaNACα18 anticipated its function as a transcriptional coactivator. The complementation of TaNACα18 in yeast and overexpression in wheat demonstrated its role in thermotolerance across the kingdom. Altogether, our results suggest that TaNACα18 imparts tolerance through tight regulation of gene expression, cell wall remodeling and activation of cell defense responses., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Fusarium head blight caused by Fusarium graminearum is a significant pathogen affecting wheat crops. During the infection process, effector proteins are secreted to modulate plant immunity and promote infection. The toxin deoxynivalenol is produced in infected wheat grains, posing a threat to human and animal health. Serine carboxypeptidases (SCPs) belong to the α/β hydrolase family of proteases and are widely distributed in plant and fungal vacuoles, as well as animal lysosomes. Research on SCPs mainly focuses on the isolation, purification, and production of a small number of fungi. The role of SCPs in plant secretion, growth and development, and stress resistance has also been extensively studied. However, their functions in F. graminearum , a fungal pathogen, remain relatively unknown. In this study, the biological functions of the FgSCP gene in F. graminearum were investigated. The study revealed that mutations in FgSCP affected the nutritional growth, sexual reproduction, and stress tolerance of F. graminearum . Furthermore, the deletion of FgSCP resulted in reduced pathogenicity and hindered the biosynthesis of deoxynivalenol. The upregulation of FgSCP expression 3 days after infection indicated its involvement in host invasion, possibly acting as a "smokescreen" to deceive the host and suppress the expression of host defensive genes. Subsequently, we confirmed the secretion ability of FgSCP and its ability to inhibit the cell death induced by INF1 in Nicotiana benthamiana cells, indicating its potential role as an effector protein in suppressing plant immune responses and promoting infection. In summary, we have identified FgSCP as an essential effector protein in F. graminearum , playing critical roles in growth, virulence, secondary metabolism, and host invasion., Competing Interests: The author(s) declare no conflict of interest.

Mitochondria-induced cell death is closely correlated with plant immune responses against pathogens. However, the molecular mechanisms by which pathogens manipulate mitochondria to suppress host resistance remain poorly understood. In this study, a haustorium-specific effector Pst11215 from the wheat stripe rust pathogen Puccinia striiformis f. sp. tritici (Pst) was characterized by host-induced gene silencing. The interaction partners regulated by Pst11215 were screened using the yeast two-hybrid system. In addition, Pst11215-mediated immune regulation modes were further determined. The results showed that Pst11215 was required for Pst virulence. Pst11215 interacted with the wheat voltage-dependent anion channel TaVDAC1, the negative regulator of wheat resistance to stripe rust, in mitochondria. Furthermore, the E3 ubiquitin ligase TaVDIP1 targeted and ubiquitinated TaVDAC1, which can be promoted by Pst11215. TaVDIP1 conferred enhanced wheat susceptibility to Pst by cooperating with TaVDAC1. Overexpression of TaVDIP1 reduced reactive oxygen species (ROS) accumulation and abnormal mitochondria. Our study revealed that Pst11215 functions as an important pathogenicity factor secreted to the host mitochondria to compromise wheat resistance to Pst possibly by facilitating TaVDIP1-mediated ubiquitination of TaVDAC1, thereby protecting mitochondria from ROS-induced impairment. This research unveils a novel regulation mode of effectors hijacking host mitochondria to contribute to pathogen infection., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)

Wheat dwarf virus (WDV, genus Mastrevirus , family Geminiviridae ) is one of the causal agents of wheat viral disease, which severely impacts wheat production in most wheat-growing regions in the world. Currently, there is little information about natural resistance against WDV in common wheat germplasms. CRISPR/Cas9 technology is being utilized to manufacture transgenic plants resistant to different diseases. In the present study, we used the CRISPR/Cas9 system targeting overlapping regions of coat protein (CP) and movement protein (MP) (referred to as CP/MP) or large intergenic region (LIR) in the wheat variety 'Fielder' to develop resistance against WDV. WDV-inoculated T 1 progenies expressing Cas9 and sgRNA for CP/MP and LIR showed complete resistance against WDV and no accumulation of viral DNA compared with control plants. Mutation analysis revealed that the CP/MP and LIR targeting sites have small indels in the corresponding Cas9-positive plants. Additionally, virus inhibition and indel mutations occurred in T 2 homozygous lines. Together, our work gives efficient results of the engineering of CRISPR/Cas9-mediated WDV resistance in common wheat plants, and the specific sgRNAs identified in this study can be extended to utilize the CRISPR/Cas9 system to confer resistance to WDV in other cereal crops such as barley, oats, and rye.

Background: Wheat proteins can be divided into water/salt-soluble protein (albumin/globulin) and water/salt-insoluble protein (gliadins and glutenins (Glu)) according to solubility. Gliadins (Glia) are one of the major allergens in wheat. The inhibition of Glia antigenicity by conventional processing techniques was not satisfactory., Results: In this study, free radical oxidation was used to induce covalent reactions. The effects of covalent reactions by high-intensity ultrasound (HIU) of different powers was compared. The enhancement of covalent grafting effectiveness between gliadin and (-)-epigallo-catechin 3-gallate (EGCG) was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry and Folin-Ciocalteu tests. HIU caused protein deconvolution and disrupted the intrastrand disulfide bonds that maintain the tertiary structure, causing a shift in the side chain structure, as proved by Fourier, fluorescence and Raman spectroscopic analysis. Comparatively, the antigenic response of the conjugates formed in the sonication environment was significantly weaker, while these conjugates were more readily hydrolyzed and less antigenic during simulated gastrointestinal fluid digestion., Conclusion: HIU-enhanced free radical oxidation caused further transformation of the spatial structure of Glia, which hid or destroyed the antigenic epitope, effectively inhibiting protein antigenicity. This study widened the application of polyphenol modification in the inhibition of wheat allergens. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Stripe rust of wheat is caused by the fungal pathogen Puccinia striiformis f. sp. tritici ( Pst ). Breeding durably resistant wheat varieties by disrupting the susceptibility ( S ) gene has an important impact on the control of wheat stripe rust. Mingxian169 (MX169) showed strong stripe rust susceptibility to all the races of Pst . However, molecular mechanisms and responsive genes underlying susceptibility of the wheat variety MX169 to Pst have not been elucidated. Here, we utilized next-generation sequencing technology to analyze transcriptomics data of "MX169" and high-resistance wheat "Zhong4" at 24, 48, and 120 h post-inoculation (hpi) with Pst . Comparative transcriptome analysis revealed 3,494, 2,831, and 2,700 differentially expressed genes (DEGs) at different time points. We observed an upregulation of DEGs involved in photosynthesis, flavonoid biosynthesis, pyruvate metabolism, thiamine metabolism, and other biological processes, suggesting their involvement in MX169's response to Pst . DEGs encoding transcription factors were also identified. Our study suggested the potential susceptibility gene resources in MX169 related to stripe rust response could be valuable for understanding the mechanisms involved in stripe rust susceptibility and for improving wheat resistance to Pst ., Importance: Our study suggests the potential susceptibility gene resources in MX169 related to stripe rust response could be valuable for understanding the mechanisms involved in stripe rust susceptibility and for improving wheat resistance to Pst ., Competing Interests: The authors declare no conflict of interest.

Background: Septoria tritici blotch (STB), caused by the foliar fungus Zymoseptoria tritici, is one of the most damaging disease of wheat in Europe. Genetic resistance against this fungus relies on different types of resistance from non-host resistance (NHR) and host species specific resistance (HSSR) to host resistance mediated by quantitative trait loci (QTLs) or major resistance genes (Stb). Characterizing the diversity of theses resistances is of great importance for breeding wheat cultivars with efficient and durable resistance. While the functional mechanisms underlying these resistance types are not well understood, increasing piece of evidence suggest that fungus stomatal penetration and early establishment in the apoplast are both crucial for the outcome of some interactions between Z. tritici and plants. To validate and extend these previous observations, we conducted quantitative comparative phenotypical and cytological analyses of the infection process corresponding to 22 different interactions between plant species and Z. tritici isolates. These interactions included four major bread wheat Stb genes, four bread wheat accessions with contrasting quantitative resistance, two species resistant to Z. tritici isolates from bread wheat (HSSR) and four plant species resistant to all Z. tritici isolates (NHR)., Results: Infiltration of Z. tritici spores into plant leaves allowed the partial bypass of all bread wheat resistances and durum wheat resistance, but not resistances from other plants species. Quantitative comparative cytological analysis showed that in the non-grass plant Nicotiana benthamiana, Z. tritici was stopped before stomatal penetration. By contrast, in all resistant grass plants, Z. tritici was stopped, at least partly, during stomatal penetration. The intensity of this early plant control process varied depending on resistance types, quantitative resistances being the least effective. These analyses also demonstrated that Stb-mediated resistances, HSSR and NHR, but not quantitative resistances, relied on the strong growth inhibition of the few Z. tritici penetrating hyphae at their entry point in the sub-stomatal cavity., Conclusions: In addition to furnishing a robust quantitative cytological assessment system, our study uncovered three stopping patterns of Z. tritici by plant resistances. Stomatal resistance was found important for most resistances to Z. tritici, independently of its type (Stb, HSSR, NHR). These results provided a basis for the functional analysis of wheat resistance to Z. tritici and its improvement., (© 2024. The Author(s).)

'Lantian 26', a leading elite winter wheat cultivar in Gansu Province since its release in 2010, exhibits high resistance or immunization to stripe rust in the adult-plant stage under a high disease pressure in Longnan (southeastern Gansu). Identifying the resistance genes in 'Lantian 26' could provide a basis for enhanced durability and high levels of resistance in wheat cultivars. Here, a segregating population was developed from a cross between a highly susceptible wheat cultivar Mingxian 169 and the highly stripe rust-resistant 'Lantian 26'. The F 2 and F 2:3 progenies of the cross were inoculated with multiple prevalent virulent races of stripe rust for adult-plant-stage-resistance evaluation in two different environments. Exon sequence alignment analysis revealed that a stripe rust resistance gene on the 718.4- to 721.2-Mb region of chromosome 7BL, tentatively named as YrLT26 , and a cosegregation sequence-tagged site (STS) marker GY17 was developed and validated using the F 2:3 population and 103 wheat cultivars. The other two resistance genes, Yr9 and Yr30 , were also identified in 'Lantian 26' using molecular markers. Therefore, the key to high and durable resistance to stripe rust at the adult stage is the combination of Yr9 , Yr30 , and YrLT26 genes in 'Lantian 26'. This could be a considerable strategy for improving the wheat cultivars with effective and durable resistance in the high-pressure region for stripe rust., Competing Interests: The author(s) declare no conflict of interest.

Stripe rust and powdery mildew are serious diseases that severely decrease the yield of wheat. Planting wheat cultivars with powdery mildew and stripe rust resistance genes is the most effective way to control these two diseases. Introducing disease resistance genes from related species into the wheat genome via chromosome translocation is an important way to improve wheat disease resistance. In this study, nine novel T1RS.1AL translocation lines were developed from the cross of wheat cultivar Chuannong25 (CN25) and a Chinese rye Qinling. The results of non-denaturing fluorescence in situ hybridization and PCR showed that all new lines were homozygous for the T1RS.1AL translocation. These new T1RS.1AL translocation lines exhibited strong resistance to stripe rust and powdery mildew. The cytogenetics results indicated that the resistance of the new lines was conferred by the 1RS chromosome arms, which came from Qinling rye. The genetic analysis indicated that there were new dominant resistance genes on the 1RS chromosome arm resistant to stripe rust and powdery mildew, and their resistance patterns were different from those of Yr9, Pm8 , and Pm17 genes. In addition, the T1RS.1AL translocation lines generally exhibited better agronomic traits in the field relative to CN25. These T1RS.1AL translocations have great potential in wheat-breeding programs in the future., Competing Interests: The author(s) declare no conflict of interest.

Background: Assessment of IgE-mediated sensitization to flour allergens is widely used to investigate flour-induced occupational asthma. The diagnostic efficiency of detecting specific IgE antibodies (sIgEs) against wheat and rye flour, however, has not been thoroughly compared with other diagnostic procedures., Objective: We sought to evaluate the diagnostic accuracy of sIgE against wheat and rye compared with specific inhalation challenge (SIC) with flour as the reference standard., Methods: This retrospective multicenter study included 264 subjects who completed an SIC with flour in eight tertiary centers, of whom 205 subjects showed a positive SIC result., Results: Compared with SIC, sIgE levels of 0.35 kU A /L or greater against wheat and rye provided similar sensitivities (84% to 85%, respectively), specificities (71% to 78%), positive predictive values (91% to 93%), and negative predictive values (56% to 61%). Increasing the threshold sIgE value to 5.10 kU A /L for wheat and to 6.20 kU A /L for rye provided a specificity of 95% or greater and further enhanced the positive predictive value to 98%. Among subjects with a positive SIC, those who failed to demonstrate sIgE against wheat and rye (n = 26) had significantly lower total serum IgE level and blood and sputum eosinophil counts and a lesser increase in postchallenge FeNO compared with subjects with a detectable sIgE., Conclusion: High levels of sIgE against wheat and/or rye flour strongly support a diagnosis of flour-induced occupational asthma without the need to perform an SIC. The absence of detectable sIgE against wheat and rye in subjects with a positive SIC seems to be associated with lower levels of T H 2 biomarkers., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Wheat blast caused by Pyricularia oryzae pathotype Triticum has spread to Asia (Bangladesh) and Africa (Zambia) from the endemic region of South America. Wheat varieties with durable resistance are needed, but very limited resistance resources are currently available. After screening tetraploid wheat accessions, we found an exceptional accession St19 ( Triticum dicoccum , KU-114). Primary leaves of St19 were resistant not only to Brazilian isolate Br48 (a carrier of Type eI of AVR-Rmg8 ) but also to Br48ΔA8, an AVR-Rmg8 disruptant of Br48, even at 30°C, suggesting that the resistance of St19 is tolerant to high temperature and controlled by a gene or genes other than Rmg8 . When an F 2 population derived from a cross between St19 and St30 (a susceptible accession of T. paleocolchicum , KU-191) was inoculated with Br48, resistant and susceptible seedlings segregated in a 3:1 ratio, indicating that resistance of St19 is conferred by a single gene. We designated this gene Rmg11 . Molecular mapping revealed that the RMG11 locus is located on the short arm of chromosome 7A. Rmg11 is effective not only against other two Brazilian isolates (Br5 and Br116.5) but also against Bangladeshi isolates (T-108 and T-109) at the seedling stage. At the heading stage, lines containing Rmg11 were highly susceptible to the Bangladeshi isolates but moderately resistant to the Brazilian isolates. Stacking of Rmg11 with Rmg8 and the 2NS segment is highly recommended to achieve durable wheat blast resistance., Competing Interests: The author(s) declare no conflict of interest.

Leaf rust is a widespread foliar wheat disease causing substantial yield losses worldwide. Slow rusting is "adult plant" resistance that significantly slows epidemic development and thereby reduces yield loss. Wheat accession CI 13227 was previously characterized as having slow-rusting resistance. To validate the quantitative trait loci (QTLs) and develop diagnostic markers for slow rusting resistance in CI 13227, a new population of recombinant inbred lines of CI 13227 × Everest was evaluated for latent period, final severity, area under the disease progress curve, and infection type in greenhouses and genotyped using genotyping-by-sequencing. Four QTLs were identified on chromosome arms 2BL, 2DS, 3BS, and 7BL, explaining 6.82 to 28.45% of the phenotypic variance for these traits. Seven kompetitive allele-specific polymorphism markers previously reported to be linked to the QTLs in two other CI 13227 populations were validated. In addition, the previously reported QLr.hwwg-7AL was remapped to 2BL (renamed QLr.hwwg-2BL ) after adding new markers in this study. Phenotypic data showed that the recombinant inbred lines harboring two or three of the QTLs had a significantly longer latent period. QLr.hwwg-2DS on 2DS showed a major effect on all rust resistance traits and was finely mapped to a 2.7-Mb interval by two newly developed flanking markers from exome capture. Three disease-resistance genes and two transporter genes were identified as the putative candidates for QLr.hwwg-2DS . The validated QTLs can be used as slow-rusting resistance resources, and the markers developed in this study will be useful for marker-assisted selection., Competing Interests: The author(s) declare no conflict of interest.

Background: Egg allergy is common and caused by sensitization to ovomucoid and/or ovalbumin. Many egg-allergic patients are able to tolerate eggs baked into other foods, such as muffins. Although heating egg extensively reduces allergens, the effect of other food ingredients on allergenicity of eggs, or the "matrix effect," is less well studied., Objective: We aimed to define how food matrices impact the matrix effect in egg allergenicity., Methods: Enzyme-linked immunosorbent assay was used to quantify ovalbumin and ovomucoid in extracts from various baked egg products: plain baked egg without a matrix, and muffins baked using either wheat flour, rice flour, or a wheat flour/banana puree mix. Allergen-specific immunoglobulin E (IgE)-blocking enzyme-linked immunosorbent assays were performed using the egg product extracts on egg-allergic patient sera to determine whether the amount of extracted egg protein in each extract correlated with how well the extracts could bind patients' egg IgE., Results: Baking eggs in any muffin matrix led to an increase in the amount of extractable ovalbumin and a decrease in the amount of extractable ovomucoid compared with plain baked egg. Compared with wheat muffins, rice muffins had more extractable ovalbumin and wheat/banana muffins had more extractable ovalbumin and ovomucoid. The egg allergens in the extracts were able to block egg-allergic patients' egg IgE., Conclusions: Food matrices affect egg allergen availability. Patients and families should be advised that substitutions in baked egg muffin recipes can affect the amount of egg allergens in foods and potentially affect the risk of food allergic reaction., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

IgE-mediated wheat allergy can take on various forms, including childhood food allergy to wheat, wheat-dependent exercise-induced anaphylaxis in young adults, baker's respiratory allergy/asthma in workers exposed to wheat flour inhalation, and contact urticaria that is caused by hydrolyzed wheat proteins in some cosmetics, and that is sometimes associated with a food allergy. Singleplex and multiplex immunoassays detect specific IgE antibodies to wheat allergenic molecular biomarkers such as omega-5 gliadin Tri a 19, lipid transfer protein Tri a 14, and alpha-amylase inhibitors. The fluorescence enzyme immunoassay with capsulated cellulose polymer solid-phase coupled allergens is a commonly used singleplex assay. Multiplex methods include the ELISA-based macroarray immunoassay using nano-bead technology and a microarray immunoassay on polymer-coated slides. Another promising diagnostic tool is the basophil activation test performed with omega-5 gliadin and other wheat protein types. Detailed comprehension of the structural and immunological features of the numerous wheat allergens significant in clinical settings is imperative for advancing diagnostic biomarkers for IgE-mediated wheat allergies.

Wheat allergy is a major type of food allergy with the potential for life-threatening anaphylactic reactions. Common wheat, Triticum aestivum (hexaploid, AABBDD genome), was developed using tetraploid wheat (AABB genome) and the ancient diploid wheat progenitor (DD genome)- Aegilops tauschii . The potential allergenicity of gluten from ancient diploid wheat is unknown. In this study, using a novel adjuvant-free gluten allergy mouse model, we tested the hypothesis that the glutenin extract from this ancient wheat progenitor will be intrinsically allergenic in this model. The ancient wheat was grown, and wheat berries were used to extract the glutenin for testing. A plant protein-free colony of Balb/c mice was established and used in this study. The intrinsic allergic sensitization potential of the glutenin was determined by measuring IgE response upon transdermal exposure without the use of an adjuvant. Clinical sensitization for eliciting systemic anaphylaxis (SA) was determined by quantifying the hypothermic shock response (HSR) and the mucosal mast cell response (MMCR) upon intraperitoneal injection. Glutenin extract elicited a robust and specific IgE response. Life-threatening SA associated and a significant MMCR were induced by the glutenin challenge. Furthermore, proteomic analysis of the spleen tissue revealed evidence of in vivo Th2 pathway activation. In addition, using a recently published fold-change analysis method, several immune markers positively and negatively associated with SA were identified. These results demonstrate for the first time that the glutenin from the ancient wheat progenitor is intrinsically allergenic, as it has the capacity to elicit clinical sensitization for anaphylaxis via activation of the Th2 pathway in vivo in mice.

Wheat species with various ploidy levels may be different regarding their immunoreactive potential in celiac disease (CD), but a comprehensive comparison of peptide sequences with known epitopes is missing. Thus, we used an untargeted liquid chromatography tandem mass spectrometry method to analyze the content of peptides with CD-active epitope in the five wheat species common wheat, spelt, durum wheat, emmer, and einkorn. In total, 494 peptides with CD-active epitope were identified. Considering the average of the eight cultivars of each species, spelt contained the highest number of different peptides with CD-active epitope (193 ± 12, mean ± SD). Einkorn showed the smallest variability of peptides (63 ± 4) but higher amounts of certain peptides compared to the other species. The wheat species differ in the presence and distribution of CD-active epitopes; hence, the entirety of peptides with CD-active epitope is crucial for the assessment of their immunoreactive potential.

Background: Low-dose oral food challenge (LD-OFC) is an approach to avoid complete elimination in high-risk patients with wheat allergy (WA). We examined the 3-year prognosis after LD-OFC among patients who passed and failed LD-OFC., Methods: Children with immediate-type WA aged ≤6 years with a history of reaction to ≤390 mg of wheat protein underwent their first LD-OFC with 52 mg (baseline LD-OFC). After passing the LD-OFC, children stepped up to 390, 1300, and 5200 mg step-by-step every 3-6 months. After failing LD-OFC, children repeated LD-OFC every 6-12 months. We assessed wheat tolerance defined as consuming 5200 mg without symptoms for 3 years after baseline LD-OFC., Results: The median age of 124 children was 2.4 years, and the wheat- and ω-5-gliadin-specific immunoglobulin E (IgE) levels (kU A /L) were 23.6 and 2.1, respectively. Upon baseline LD-OFC, 57% passed (LD-tolerant), whereas 43% failed (LD-reactive). Within 3 years, 38% of the LD-reactive group passed re-administered LD-OFC, and 70% of all participants avoided complete elimination. The percentage of the participants who became capable of consuming 390 mg (87% vs. 18%), 1300 mg (78% vs. 13%), and acquired tolerance (70% vs. 13%) was significantly higher in the LD-tolerant group than in the LD-reactive group (p < 0.001). Predictors of persistent WA in the LD-tolerant group were older age (adjusted odds ratio, 1.63), ω-5-gliadin-specific IgE level (1.62 per 10-fold increase), and other food allergies (1.94)., Conclusions: LD-tolerant patients frequently acquired wheat tolerance within 3 years. Even if once positive, one-third could pass the re-administered LD-OFC within 3 years., (Copyright © 2024 Japanese Society of Allergology. Published by Elsevier B.V. All rights reserved.)

Employing race-specific resistance genes remains an effective strategy to protect wheat from leaf rust caused by Puccinia triticina (Pt) worldwide, while the newly emerged Pt races, owing to rapid genetic evolution, frequently overcome the immune response delivered by race-specific resistance genes. The molecular mechanisms underlying the newly evolved virulence Pt pathogen remain unknown. Here, we identified an avirulence protein AvrLr15 from Pt that induced Lr15-dependent immune responses. Heterologously produced AvrLr15 triggered pronounced cell death in Lr15-isogenic wheat leaves. AvrLr15 contains a functional signal peptide, localized to the plant nucleus and cytosol and can suppress BAX-induced cell death. Evasion of Lr15-mediated resistance in wheat was associated with a deletion and point mutations of amino acids in AvrLr15 rather than AvrLr15 gene loss in the Lr15-breaking Pt races, implying that AvrLr15 is required for the virulence function of Pt. Our findings identified the first molecular determinant of wheat race-specific immunity and facilitated the identification of the first AVR/R gene pair in the Pt-wheat pathosystem, which will provide a molecular marker to monitor natural Pt populations and guide the deployment of Lr15-resistant wheat cultivars in the field., (© 2024 The Author(s). Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)

Actin filaments and their associated actin-binding proteins play key roles in plant innate immune signaling. CAP1, or cyclase-associated protein 1, is an important regulatory factor of the actin cytoskeleton-associated signaling network and was hypothesized here to be involved in resistance against wheat stripe rust because TaCAP1 expression was upregulated in response to Puccinia striiformis f. sp. tritici ( Pst ). Downregulation of TaCAP1 expression led to decreased resistance against Pst , in contrast to increased resistance upon TaCAP1 overexpressing, as demonstrated by the changes of phenotypes and hyphal growth. We found increased expression of pathogenesis-responsive or relative related genes and disease grade changed in TaCAP1 overexpressing plants. Our results also showed TaCAP1- regulated host resistance to Pst by inducing the production and accumulation of reactive oxygen species and mediating the salicylic acid signaling pathway. Additionally, TaCAP1 interacted with chlorophyll a/b-binding proteins TaLHCB1.3 and TaLHCB1.4, also known as the light-harvesting chlorophyll-protein complex II subunit B, which belong to the light-harvesting complex II protein family. Silencing of two TaLHCB1 genes showed higher susceptibility to Pst , which reduced wheat resistance against Pst . Therefore, the data presented herein further illuminate our understanding that TaCAP1 interacts with TaLHCB1s and functions as a positive regulator of wheat resistance against stripe rust., Competing Interests: The author(s) declare no conflict of interest.

Effector proteins are central to the success of plant pathogens, while immunity in host plants is driven by receptor-mediated recognition of these effectors. Understanding the molecular details of effector-receptor interactions is key for the engineering of novel immune receptors. Here, we experimentally determined the crystal structure of the Puccinia graminis f. sp. tritici (Pgt) effector AvrSr27, which was not accurately predicted using AlphaFold2. We characterised the role of the conserved cysteine residues in AvrSr27 using in vitro biochemical assays and examined Sr27-mediated recognition using transient expression in Nicotiana spp. and wheat protoplasts. The AvrSr27 structure contains a novel β-strand rich modular fold consisting of two structurally similar domains that bind to Zn 2+ ions. The N-terminal domain of AvrSr27 is sufficient for interaction with Sr27 and triggering cell death. We identified two Pgt proteins structurally related to AvrSr27 but with low sequence identity that can also associate with Sr27, albeit more weakly. Though only the full-length proteins, trigger Sr27-dependent cell death in transient expression systems. Collectively, our findings have important implications for utilising protein prediction platforms for effector proteins, and those embarking on bespoke engineering of immunity receptors as solutions to plant disease., (© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.)

The plant rapid alkalinization factor (RALF) peptides function as key regulators in cell growth and immune responses through the receptor kinase FERONIA (FER). In this study, we report that the transcription factor FgPacC binds directly to the promoter of FgRALF gene, which encodes a functional homologue of the plant RALF peptides from the wheat head blight fungus Fusarium graminearum (FgRALF). More importantly, FgPacC promotes fungal infection via host immune suppression by activating the expression of FgRALF. The FgRALF peptide also exhibited typical activities of plant RALF functions, such as inducing plant alkalinization and inhibiting cell growth, including wheat (Triticum aestivum), tomato (Solanum lycopersicum) and Arabidopsis thaliana. We further identified the wheat receptor kinase FERONIA (TaFER), which is capable of restoring the defects of the A. thaliana FER mutant. In addition, we found that FgRALF peptide binds to the extracellular malectin-like domain (ECD) of TaFER (TaFER ECD ) to suppress the PAMP-triggered immunity (PTI) and cell growth. Overexpression of TaFER ECD in A. thaliana confers plant resistance to F. graminearum and protects from FgRALF-induced cell growth inhibition. Collectively, our results demonstrate that the fungal pathogen-secreted RALF mimic suppresses host immunity and inhibits cell growth via plant FER receptor. This establishes a novel pathway for the development of disease-resistant crops in the future without compromising their yield potential., (© 2024 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)

Small RNAs (sRNAs) are involved in gene silencing in multiple ways, including through cross-kingdom transfers from parasites to their hosts. Little is known about the evolutionary mechanisms enabling eukaryotic microbes to evolve functional mimics of host small regulatory RNAs. Here, we describe the identification and functional characterization of SINE&#95;sRNA1 , an sRNA family derived from highly abundant short interspersed nuclear element (SINE) retrotransposons in the genome of the wheat powdery mildew pathogen. SINE&#95;sRNA1 is encoded by a sequence motif that is conserved in multiple SINE families and corresponds to a functional plant microRNA (miRNA) mimic targeting Tae&#95;AP1 , a wheat gene encoding an aspartic protease only found in monocots. Tae&#95;AP1 has a novel function enhancing both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), thereby contributing to the cross activation of plant defenses. We conclude that SINE&#95;sRNA1 and Tae&#95;AP1 are functional innovations, suggesting the contribution of transposons to the evolutionary arms race between a parasite and its host. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license., Competing Interests: The author(s) declare no conflict of interest.

Plants have evolved a sophisticated immunity system for specific detection of pathogens and rapid induction of measured defences. Over- or constitutive activation of defences would negatively affect plant growth and development. Hence, the plant immune system is under tight positive and negative regulation. MAP kinase phosphatase1 (MKP1) has been identified as a negative regulator of plant immunity in model plant Arabidopsis. However, the molecular mechanisms by which MKP1 regulates immune signalling in wheat (Triticum aestivum) are poorly understood. In this study, we investigated the role of TaMKP1 in wheat defence against two devastating fungal pathogens and determined its subcellular localization. We demonstrated that knock-down of TaMKP1 by CRISPR/Cas9 in wheat resulted in enhanced resistance to rust caused by Puccinia striiformis f. sp. tritici (Pst) and powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt), indicating that TaMKP1 negatively regulates disease resistance in wheat. Unexpectedly, while Tamkp1 mutant plants showed increased resistance to the two tested fungal pathogens they also had higher yield compared with wild-type control plants without infection. Our results suggested that TaMKP1 interacts directly with dephosphorylated and activated TaMPK3/4/6, and TaMPK4 interacts directly with TaPAL. Taken together, we demonstrated TaMKP1 exert negative modulating roles in the activation of TaMPK3/4/6, which are required for MAPK-mediated defence signalling. This facilitates our understanding of the important roles of MAP kinase phosphatases and MAPK cascades in plant immunity and production, and provides germplasm resources for breeding for high resistance and high yield., (© 2024 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)

Wheat stem rust, which is caused by Puccinia graminis f. sp. tritici ( Pgt ), is a highly destructive disease that affects wheat crops on a global scale. In this study, the reactions of 150 bread wheat varieties were evaluated for natural Pgt infection at the adult-plant stage in the 2019-2020 and 2020-2021 growing seasons, and they were analyzed using specific molecular markers to detect stem rust resistance genes ( Sr22 , Sr24 , Sr25 , Sr26 , Sr31 , Sr38 , Sr50 , and Sr57 ). Based on phenotypic data, the majority of the varieties (62%) were resistant or moderately resistant to natural Pgt infection. According to molecular results, it was identified that Sr57 was present in 103 varieties, Sr50 in nine varieties, Sr25 in six varieties, and Sr22 , Sr31 , and Sr38 in one variety each. Additionally, their combinations Sr25 + Sr50 , Sr31 + Sr57 , Sr38 + Sr50 , and Sr38 + Sr57 were detected in these varieties. On the other hand, Sr24 and Sr26 were not identified. In addition, many varieties had low stem rust scores, including a large minority that lacked Sr57 . These varieties must have useful resistance to stem rust and could be the basis for selecting greater, possibly durable resistance., Competing Interests: The author declares that they have no competing interests., (© 2024 Cat.)

Leaf rust, caused by Puccinia triticina , is a major cause of wheat yield losses globally, and novel leaf rust resistance genes are needed to enhance wheat leaf rust resistance. Teremai Bugdai is a landrace from Uzebekistan that is highly resistant to many races of P. triticina in the United States. To unravel leaf rust resistance loci in Teremai Bugdai, a recombinant inbred line (RIL) population of Teremai Bugdai × TAM 110 was evaluated for response to P. triticina race Pt54-1 (TNBGJ) and genotyped using single nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing (GBS). Quantitative trait loci (QTL) analysis using 5,130 high-quality GBS-SNPs revealed three QTLs, QLr-Stars-2DS , QLr-Stars-6BL , and QLr.Stars-7BL , for leaf rust resistance in two experiments. QLr-Stars-2DS , which is either a new Lr2 allele or a new resistance locus, was delimited to an ∼19.47-Mb interval between 46.4 and 65.9 Mb on 2DS and explained 31.3 and 33.2% of the phenotypic variance in the two experiments. QLr-Stars-6BL was mapped in an ∼84.0-kb interval between 719.48 and 719.56 Mb on 6BL, accounting for 33 to 36.8% of the phenotypic variance in two experiments. QLr.Stars-7BL was placed in a 350-kb interval between 762.41 and 762.76 Mb on 7BL and explained 4.4 to 5.3% of the phenotypic variance. Nine GBS-SNPs flanking these QTLs were converted to kompetitive allele specific PCR (KASP) markers, and these markers can be used to facilitate their introgression into locally adapted wheat lines., Competing Interests: The author(s) declare no conflict of interest.

Powdery mildew, caused by Blumeria graminis f. sp. tritici ( Bgt ), is a serious threat to wheat ( Triticum aestivum L.) production. Narrow genetic basis of common wheat boosted the demand for diversified donors against powdery mildew. Aegilops tauschii Coss (2 n = 2 x = DD) and emmer wheat (2 n = 4 x = AABB), as the ancestor species of common wheat, are important gene donors for genetic improvement of common wheat. In this study, a total of 71 Ae. tauschii and 161 emmer wheat accessions were first evaluated for their powdery mildew resistance using the Bgt isolate E09. Thirty-three Ae. tauschii (46.5%) and 108 emmer wheat accessions (67.1%) were resistant. Then, all these accessions were tested by the diagnostic markers for 21 known Pm genes. The results showed that Pm2 alleles were detected in all the 71 Ae. tauschii and only Pm4 alleles were detected in 20 of 161 emmer wheat accessions. After haplotype analysis, we identified four Pm4 alleles ( Pm4a , Pm4b , Pm4d , and Pm4f ) in the emmer wheat accessions and three Pm2 alleles ( Pm2d , Pm2e , and Pm2g ) in the Ae . tauschii . Further resistance spectrum analysis indicated that these resistance accessions displayed different resistance reactions to different Bgt isolates, implying they may have other Pm genes apart from Pm2 and/or Pm4 alleles. Notably, a new Pm2 allele, Pm2S , was identified in Ae . tauschii , which contained a 64-bp deletion in the first exon and formed a new termination site at the 513th triplet of the shifted reading frame compared with reported Pm2 alleles. The phylogenetic tree of Pm2S showed that the kinship of Pm2S was close to Pm2h . To efficiently and accurately detect Pm2S and distinguish with other Pm2 alleles in Ae. tauschii background, a diagnostic marker, YTU-QS-3 , was developed, and its effectiveness was verified. This study provided valuable Pm alleles and enriched the genetic diversity of the powdery mildew resistance in wheat improvement., Competing Interests: The author(s) declare no conflict of interest.

Competing Interests: Disclosures The authors have no conflicts of interest to report.

Wheat blast, caused by the fungus Magnaporthe oryzae, threatens global cereal production since its emergence in Brazil in 1985 and recently spread to Bangladesh and Zambia. Here we demonstrate that the AVR-Rmg8 effector, common in wheat-infecting isolates, is recognized by the gene Pm4, previously shown to confer resistance to specific races of Blumeria graminis f. sp. tritici, the cause of powdery mildew of wheat. We show that Pm4 alleles differ in their recognition of different AVR-Rmg8 alleles, and some confer resistance only in seedling leaves but not spikes, making it important to select for those alleles that function in both tissues. This study has identified a gene recognizing an important virulence factor present in wheat blast isolates in Bangladesh and Zambia and represents an important first step towards developing durably resistant wheat cultivars for these regions., (© 2024. The Author(s).)

Wheat blast, a devastating disease having spread recently from South America to Asia and Africa, is caused by Pyricularia oryzae (synonym of Magnaporthe oryzae) pathotype Triticum, which first emerged in Brazil in 1985. Rmg8 and Rmg7, genes for resistance to wheat blast found in common wheat and tetraploid wheat, respectively, recognize the same avirulence gene, AVR-Rmg8. Here we show that an ancestral resistance gene, which had obtained an ability to recognize AVR-Rmg8 before the differentiation of Triticum and Aegilops, has expanded its target pathogens. Molecular cloning revealed that Rmg7 was an allele of Pm4, a gene for resistance to wheat powdery mildew on 2AL, whereas Rmg8 was its homoeologue on 2BL ineffective against wheat powdery mildew. Rmg8 variants with the ability to recognize AVR-Rmg8 were distributed not only in Triticum spp. but also in Aegilops speltoides, Aegilops umbellulata and Aegilops comosa. This result suggests that the origin of resistance gene(s) recognizing AVR-Rmg8 dates back to the time before differentiation of A, B, S, U and M genomes, that is, ~5 Myr before the emergence of its current target, the wheat blast fungus. Phylogenetic analyses suggested that, in the evolutionary process thereafter, some of their variants gained the ability to recognize the wheat powdery mildew fungus and evolved into genes controlling dual resistance to wheat powdery mildew and wheat blast., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)