Qiuhong Wu

The stripe rust resistance molecular module '1347B', comprising Yr9-1RS/1BL , Yr30-3BS , YrZH22-4BL , and YrZH84-7BL , could provide stable and durable stripe rust resistance without a yield penalty in wheat breeding program. Wheat stripe rust is a significant epidemiological disease that severely impacts wheat production. The aggregation of multiple stripe rust resistance genes constitutes a pivotal breeding strategy for reducing pathogen evolution of virulence and enhancing the resistance level in wheat. Investigating the resistance conferred by various combinations of stripe rust resistance genes and assessing their impact on wheat yield are essential for understanding the synergistic regulatory mechanisms of these genes on host immunity and yield. In this study, 254 F₇ recombinant inbred lines (RILs) derived from the cross ZK331/ZK32 were evaluated for stripe rust severity at the adult-plant stage and thousand-kernel weight (TKW) across six environments over a two-year period. Through QTL mapping and molecular marker detection, four stripe rust resistance genes, Yr9 (1RS/1BL), Yr30 (3BS), YrZH22 (4BL), and YrZH84 (7BL) were identified in the RIL population. The results demonstrated that pyramiding these genes conferred a high level of adult plant stage resistance to stripe rust. Analysis of agronomic traits, including TKW, plant height, spike length, and kernel number per spike, in RIL population with different combinations of these genes revealed no adverse effects under rust-free conditions and a highly significant positive effect under stripe rust infection. The molecular module '1347B', comprising Yr9-1RS/1BL , Yr30-3BS , YrZH22-4BL , and YrZH84-7BL , provided stripe rust resistance across multiple growth stages without a yield penalty. This study elucidates the resistance efficacy and yield stability provided by the '1347B' module, providing a valuable genetic resource and theoretical foundation for designing high-yielding wheat varieties with enhanced stripe rust resistance.

Wheat is a major staple crop for over one-third of the world’s population, crucial for global food security, economic stability and cultural traditions. Recently, single-cell and spatial omics approaches have transformed biological discovery, primarily in medical and animal sciences, and they are now beginning to be applied in plant research. Here we summarize the technical innovations and feasibility of spatial omics applications in wheat research, particularly for understanding developmental and environmental responses, thereby potentially enhancing wheat breeding. We highlight how these tools can reveal spatial and temporal patterns in gene expression, cellular heterogeneity and tissue organization in wheat. Furthermore, we propose developing a spatially resolved single-cell atlas of wheat across its life cycle to facilitate breakthroughs in basic research and potential applications in breeding. To achieve these goals, we advocate for a Wheat Spatial Omics Consortium to foster worldwide collaboration for overcoming barriers and developing sustainable and climate-resilient wheat.

Key message The wheat powdery mildew resistance gene PmPBDH was fine mapped to a 788.20-kb genomic interval on chromosome arm 4AL. Abstract The powdery mildew resistance gene PmPBDH was identified in wheat breeding line PBDH1607. To fine map PmPBDH, an F_2:3 population of 5000 individuals derived from the cross PBDH1607 × Huixianhong was used for recombinant screening. Combining PacBio SMRT long-read genome sequencing, PmPBDH is fine mapped to a 788.20 kb interval (chr4A:737865053–738653247 bp) based on the reference genome of Chinese Spring (IWGSC RefSeq v2.1). Comparative genomic analysis reveals poor collinearity of this region across different Triticum species, indicating complex structural variations of this candidate interval. Within this interval, 16 high confidence genes are annotated according to IWGSC RefSeq v2.1. Expression profiling following Bgt inoculation and sequence variation analysis reveals TraesCS4A03G1174000, encoding the RPP13 nucleotide-binding leucine-rich repeat (NLR) protein, as the pivotal candidate gene for PmPBDH. Three closely linked or co-segregated markers are screened for optimizing the efficient transfer of PmPBDH in breeding practices. This study provides valuable genetic resource and molecular tool for improving resistance against powdery mildew in wheat.

Wheat relatives harbour abundant variations that can be used for genetic improvement against diseases through complex domestication processes. Here, we report the isolation of the powdery mildew resistance gene Pm37 in common wheat through a strategy integrating map-based cloning, PacBio SMRT long-read genome sequencing, mutagenesis, barley stripe mosaic virus-induced gene silencing and stable transformation. Pm37 encodes a coiled-coil nucleotide-binding site leucine-rich repeat (CC-NBS-LRR) receptor. The cell death-inducing activity of PM37 in Nicotiana benthamiana is mainly mediated by its CC domain. De novo genome sequencing and haplotype analysis reveal that Pm37 may be derived from Triticum monococcum, and transferred into common wheat through T. timopheevii. Interestingly, Pm37 is a susceptible allele of the stem rust resistance locus Sr22, and also confers moderate resistance to leaf rust. Our findings identify a gene characterized by allelic variation-driven functional divergence in response to different wheat diseases.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating wheat disease worldwide. We dissected the genetic basis of adult-plant resistance (APR) to stripe rust in a recombinant inbred line (RIL) population derived from the cross Tianmin 668 × Jingshuang 16. Following inoculation with prevalent Pst races CYR32, CYR33, and CYR34, phenotypic evaluation across three growing seasons revealed quantitative inheritance of the resistance with high heritability. Seven APR QTL were identified. The resistant parent Tianmin 668 contributed three QTL on chromosomes 2AS, 2BS, and 2BL. The most stable QTL, QYrtj-2AS explaining 9.39–16.73% of the phenotypic variance, was confirmed to be Yr17 using 2NS-specific markers and whole-genome resequencing. The susceptible parent Jingshuang 16 also contributed four QTL, including QYrtj-3BS (Yr30) and QYrtj-6BS. These QTL explained 14.15–15.06% and 12.78–13.66% of the phenotypic variance, respectively, but exhibited less environmental stability than Yr17. Pyramiding QYrtj-2AS (Yr17) with the two additional QTL from Tianmin 668 on chromosome 2B reduced the maximum disease severity by 33%, demonstrating significant additive effects. These results demonstrate the value of both major-effect QTL, such as QYrtj-2AS (Yr17) and QYrtj-2BL, and environmentally responsive QTL derived even from susceptible parents for breeding. This study provides valuable genomic resources and molecular markers for pyramiding durable stripe rust resistance in wheat.

Wheat ( Triticum aestivum L.) is one of the world's most important food crops and its production is frequently threatened by diseases caused by several biotrophic pathogens, including stripe rust, leaf rust, stem rust and powdery mildew. Identifying and cloning genes that confer resistance to multiple‐diseases hold significant value for breeding wheat cultivars with broad‐spectrum disease resistance. In this study, a wheat autoimmunity ‐ B2 ( WAI ‐ B2 ) gene is cloned from an ethyl methanesulfonate (EMS)‐induced wheat autoimmunity mutant, 8P4087, and its role in resistance against multiple foliar diseases is characterized. WAI‐B2 encodes a unique transmembrane protein that provides resistance to powdery mildew, stripe rust, leaf rust and stem rust in wheat. Further analysis reveals that WAI‐B2 interacts with the TaHsp90 and TaHsp70, which is crucial for cell stabilization, signal transduction and programed cell death (PCD). Used AlphaFold 2 and SWISS‐MODEL to predict the optimal amino acid substitution and hydrogen bond interaction sites, a series of new WAI‐B2 alleles is designed, and alleles capable of causing mild cell death in N . benthamiana are obtained. This study provides valuable insights into the potential of artificial intelligence (AI)‐assisted approaches for designing disease‐resistant crops in the future.

SUMMARY: Nucleotide-binding and leucine-rich repeat (LRR) receptors (NLRs) are widespread intracellular immune sensors across kingdoms. In plants, the G10-type coiled-coil (CC _G10 )-NLRs form a distinct phylogenetic clade that remains poorly characterized. Here, we identified a gain-of-function (GOF) mutant of Wheat Autoimmunity 3 ( WAI3 ), designated WAI3 ^GOF , which encodes a constitutively activated CC _G10 -NLR protein due to an amino acid substitution. Cryo-EM structural analysis revealed that activated WAI3 assembles into a distinctive octameric resistosome. Arabidopsis RPS2, another CC _G10 -NLR, also forms an octamer, indicating a conserved structural property across monocot and dicot plants. The WAI3 resistosome mediates a prolonged and sustained increase in cytosolic calcium influx, facilitated by a unique channel architecture arising from its divergent CC domain configuration. Notably, this domain arrangement may be shared by many plant NLRs that lack the conserved EDVID motif in their CC domains. Our findings uncover a previously uncharacterized resistosome structure and provide insights into plant immune receptor plasticity.

Key message We identified Rht28, a novel dwarf gene on the wheat chromosome arm 2AL, and investigated its effect on important agronomic traits. Abstract The genetic dissection of wheat plant height (PH) and the identification of new dwarf or semi-dwarf genes will help breeders to improve yield potential. In this study, QPh-2A.2, a newly discovered locus controlling PH and explaining 7.29%-14.61% of the phenotypic variation across ten environments, was identified using a recombinant inbred line (RIL) population derived from the cross Yanda 1817 × Beinong 6 through a previously constructed single nucleotide polymorphism (SNP) genetic linkage map. To confirm the stability and effect of QPh-2A.2, 22 tightly linked markers were developed based on the released Chinese Spring (CS) reference genome sequence, and a high-density genetic linkage map of the target locus was constructed. QPh-2A.2 is a newly discovered locus controlling PH in wheat, which is temporarily designated Rht28. Additionally, Rht28 was found to have significant effects on thousand-grain weight, grain width, grain thickness, and grain weight per spike, as evaluated in the RIL population, while other agronomic traits related to flag leaf and spike traits were not significantly affected. Moreover, using a large segregating population and extensive progeny tests, we mapped Rht28 within a 3.17-Mb physical region between the markers WBUA4036 and WBUA4413 on the long arm of chromosome 2A. This targeted region contains 51 annotated genes according to CS v2.1 reference genome sequence, and two of these were speculated to be candidates for Rht28. Exploring new dwarf genes is a vital route to breed lodging-resistant wheat cultivars. This study also provides important information for Rht28 marker-assisted selection in wheat breeding programs.

Improving wheat yield is essential to meet the increasing demand for food production. This study aims to identify quantitative trait loci (QTL) associated with grain traits and plant height (PH) in winter wheat, using a recombinant inbred line (RIL) population derived from a cross between Zhongke 331 and Nongda 399. The RIL population was genotyped using the 16K GenoBaits Wheat single nucleotide polymorphism (SNP) array. A genetic linkage map was established, comprising 14,868 SNPs and spanning 3846.91 cM, with an average interval of 1.11 cM between markers. These SNPs were categorized into 3463 SNP bin markers, with 1653, 1508, and 302 located in the A, B, and D sub-genomes, respectively. QTL analysis for thousand-grain weight (TGW), grain length (GL), grain width (GW), and PH revealed 61 QTL influencing these traits across six environments. Loci qPH-4B.1 and qPH-4D.1 were consistently detected in five environments. QTL clusters with pleiotropic effects that regulate multiple grain traits were identified on chromosomes 4B and 4D. Furthermore, the combination of qPH-4B.1 and qPH-4D.1 resulted in a reduced plant height compared to the presence of either locus alone, indicating an additive effect between these loci.