The effect of cadmium on soil and plants, and the influence of Serendipita indica (Piriformospora indica) in mitigating cadmium stress.

Due to environmental pollution, the risk of cadmium stress for crops is soaring, so researchers are exploring inexpensive solutions to enhance cultivated crops in contaminated soil. Using microorganisms to reduce cadmium risk has been one of the most effective strategies in recent decades. Serendipita indica (Piriformospora indica) is one of the best endophyte fungi that, in addition to reducing heavy metal stress for crops, can significantly reduce the threat of other abiotic stresses. As part of this research, cadmium in soil has been investigated, as well as its effects on plants' morphophysiological and biochemical characteristics. The present review has also attempted to identify the role of Serendipita indica in improving the growth and performance of crops, as well as its possible effect on reducing the risk of cadmium. The results showed that Serendipita indica enhance the growth and productivity of plants in contaminated environments by improving soil quality, reducing cadmium absorption, improving the activity of antioxidant enzymes and secondary metabolites, raising water and mineral absorption, and altering morphophysiological structures.

Diabetic foot exacerbates gut mycobiome dysbiosis in adult patients with type 2 diabetes mellitus: revealing diagnostic markers.

Type 2 diabetes mellitus (T2DM) is globally recognized as a significant health concern, with diabetic foot (DF) identified as a severe long-term complication that can lead to tissue death or amputation. The discovery of the impact of mycobiota, a diverse group of multicellular eukaryotes in the gut microbiome, on the onset of endocrine disorders holds great significance. Therefore, this research aimed to examine variations in fungal mycobiome and identify potential biomarkers for T2DM and T2DM-DF. Fecal and blood samples were collected from 33 individuals with T2DM, 32 individuals with T2DM-DF, and 32 healthy individuals without any health conditions (HC). Blood samples were used for laboratory parameters analysis, while total DNA was extracted from fecal samples and sequenced using Illumina 18s rRNA. Bioinformatics tools were employed to analyze fungal abundance and diversity, revealing differentially expressed fungal species and signature fungi that distinguished between T2DM, T2DM-DF, and HC groups. Firstly, significant alterations in some laboratory parameters were observed among the three groups, which also differed between T2DM and T2DM-DF. The diversity of gut fungi in T2DM and T2DM-DF significantly differed from that of the HC group; however, more pronounced changes were observed in T2DM-DF. Additionally, two significantly altered phyla, Ascomycota and Basidiomycota, were identified with higher Ascomycota abundance but lower Basidiomycota abundance in both the T2DM and T2DM-DF compared to the HC group. Furthermore, the top 15 fungi showing significant changes at the species level included a notable decrease in Rhodotorula_mucilaginosa abundance in patients with T2DM compared to HC and a substantial increase in unclassified_g_Candida abundance specifically seen only among patients with T2DM-DF, but not among those diagnosed with T2DM or HC. Thirdly, KEGG was employed to analyze enzyme expression across the three groups, revealing a more pronounced alteration in gut fungal function within T2DM-DF compared to T2DM. Subsequently, to accurately identify signature fungi in each group, a random forest was utilized to rank the top 15 significant fungi. Notably, 11 fungi were identified as potential biomarkers for distinguishing T2DM or T2DM-DF from HC, while eight fungi could discriminate between T2DM and T2DM-DF. Furthermore, receiver operating characteristic curve (ROC) analysis demonstrated enhanced accuracy of predicted outcomes. These findings suggest that changes in fungal mycobiome are closely associated with the progression and complications of T2DM and DF, offering promising prospects for diagnosis and treatment.

Wheat improvement through advances in single nucleotide polymorphism (SNP) detection and genotyping with a special emphasis on rust resistance.

KEY MESSAGE: Single nucleotide polymorphism (SNP) markers in wheat and their prospects in breeding with special reference to rust resistance. Single nucleotide polymorphism (SNP)-based markers are increasingly gaining momentum for screening and utilizing vital agronomic traits in wheat. To date, more than 260 million SNPs have been detected in modern cultivars and landraces of wheat. This rapid SNP discovery was made possible through the release of near-complete reference and pan-genome assemblies of wheat and its wild relatives, coupled with whole genome sequencing (WGS) of thousands of wheat accessions. Further, genotyping customized SNP sites were facilitated by a series of arrays (9 to 820Ks), a cost effective substitute WGS. Lately, germplasm-specific SNP arrays have been introduced to characterize novel traits and detect closely linked SNPs for marker-assisted breeding. Subsequently, the kompetitive allele-specific PCR (KASP) assay was introduced for rapid and large-scale screening of specific SNP markers. Moreover, with the advances and reduction in sequencing costs, ample opportunities arise for generating SNPs artificially through mutations and in combination with next-generation sequencing and comparative genomic analyses. In this review, we provide historical developments and prospects of SNP markers in wheat breeding with special reference to rust resistance where over 50 genetic loci have been characterized through SNP markers. Rust resistance is one of the most essential traits for wheat breeding as new strains of the Puccinia fungus, responsible for rust diseases, evolve frequently and globally.

Completion of the genome sequence of Oidiodendron maius splipalmivirus 1.

Mycoviruses with an unprecedented genome organization, featuring the RNA-directed RNA polymerase (RdRp) palm domain coding sequence being split into two distinct genome segments, have been found recently in a few fungi and oomycetes of different lineages and have been proposed to be named "splipalmiviruses". One of these, Oidiodendron maius splipalmivirus 1 (OmSPV1), has been detected in the ericoid mycorrhizal fungus Oidiodendron maius, and it has been proposed to be bisegmented. Here, we complete the genome sequence of this virus by describing a third RNA segment, which is 2000 nt long and whose terminal sequences are identical to those of the other two segments of OmSPV1. This segment contains a single open reading frame that codes for a protein with unknown function and has a low level of sequence identity (47%) to the putative protein encoded by the third segment of another splipalmivirus from Magnaporthe oryzae: Magnaporthe oryzae narnavirus virus 1 (MoNV1). Based on these features, we propose the RNA segment to be the third segment of the OmSPV1 genome.

Varied sensitivity to boscalid among different Clarireedia species causing dollar spot in turfgrass.

Dollar spot, a highly destructive turfgrasses disease worldwide, is caused by multiple species within the genus Clarireedia. Previous research indicated varying sensitivity to boscalid among Clarireedia populations not historically exposed to succinate dehydrogenase inhibitors (SDHIs). This study confirms that the differential sensitivity pattern is inherent among different Clarireedia spp., utilizing a combination of phylogenetic analyses, in vitro cross-resistance assays, and genetic transformation of target genes with different mutations. Furthermore, greenhouse inoculation experiments revealed that the differential boscalid sensitivity did not lead to pathogenicity issues or fitness penalties, thereby not resulting in control failure by boscalid. This research underscores the importance of continuous monitoring of fungicide sensitivity trends and highlights the complexity of chemical control of dollar spot due to the inherent variability in fungicide sensitivity among different Clarireedia spp.

Determining Gene Order Patterns in the Suillus and Boletales through Comparative Analysis of Their Mitogenomes.

Suillus is one of the most important genera of ectomycorrhizal fungi. As a model for studying host specificity, its molecular fragments and nuclear genome have been analyzed. However, its mitochondrial genome has not yet been reported. In this study, we assembled five mitogenomes of Suillus and analyzed and compared their basic characteristics. Owing to the large number of introns as well as intergenic regions, the mitogenomic lengths of species of Suillus were greater than those of other species of Boletales. We identified two main patterns of gene order arrangement in the members of the order Boletales. The Ka/Ks values of 15 protein-coding genes were <1 for the mitochondrial genes of 39 Boletales species, indicating their conserved evolution. Phylogenetic trees, reconstructed using the mitogenomes, indicated that the genus Suillus was monophyletic. Phylogenetic results based on the internal transcribed spacer region and mitogenome were used to confirm the distribution of Suillus placidus in China. The results showed that the mitogenome was superior in distinguishing species compared with a single molecular fragment. This is the first study to investigate the mitogenome of Suillus, enriching the mitogenome information and providing basic data for the phylogeny, resource conservation, and genetic diversity of this genus.

Research on the Cell Wall Breaking and Subcritical Extraction of Astaxanthin from Phaffia rhodozyma.

This study focused on developing an effective cell wall-breaking method for Phaffia rhodozyma, followed by utilizing subcritical fluid extraction to isolate, extract, and concentrate astaxanthin from the complex fermentation products of P. rhodozyma. A comprehensive comparison of seven distinct methods for disrupting cell walls, including dimethyl sulfoxide treatment, lactic acid treatment, sodium hydroxide treatment, ß-glucanase enzymatic digestion, ß-mannanase enzymatic digestion, and a combined enzymatic treatment involving both ß-mannanase and ß-glucanase was conducted. The results identified the lactic acid method as the most effective in disrupting the cell walls of P. rhodozyma. The software, Design Expert, was used in the process of extracting astaxanthin from cell lysates using a subcritical extraction method. Through fitting analysis and response surface optimization analysis by Design Expert, the optimal extraction conditions were determined as follows: an extraction temperature of 41 °C, extraction frequency of two times, and extraction time of 46 min. These parameters facilitated the efficient extraction, concentration, and enrichment of astaxanthin from P. rhodozyma, resulting in an astaxanthin concentration of 540.00 mg/L. This result can establish the foundation for its high-value applications.

Chemical and physical characteristics of wheat root mucilage influenced by Serendipita indica symbiosis: a comparison among four cultivars.

Although there is evidence to suggest that the endophytic fungus Serendipita indica plays a crucial role in enhancing plant tolerance against biotic/abiotic stressors, less is known about the impacts of this symbiosis association on root mucilage chemical composition and its physical functions. The mucilage of inoculated and non-inoculated seedlings of four wheat cultivars (i.e., Roshan, Ghods, Kavir and Pishtaz) were extracted using an aeroponic method. Total solute concentration (TCm), carbon content (Cmucilage), electrical conductivity (EC), pH, fatty acids, surface tension (σm), and viscosity (ηm) of mucilage were measured. Ghods and Kavir had the highest and lowest root colonization percents, respectively. Saturated fatty acids, including palmitic and stearic acids, were dominant over unsaturated fatty acids in wheat root mucilage. However, their compositions were significantly different among wheat cultivars. S. indica colonization, especially for Ghods, increased the TCm, Cmucilage, and palmitic acid. Moreover, root mucilage of S. indica-inoculated Ghods had lower σm and greater ηm. An increased amount of powerful surfactants like palmitic acid in the mucilage of S. indica inoculated treatments led to lower σm and greater ηm. Such studies provide further support for the idea that plant-released mucilage plays a major role in modifying the physical environment of the rhizosphere. This knowledge toward truly understanding the rhizosphere can be potentially used for improving the rhizosphere soil quality and increasing crop growth and yield.

Comprehensive analysis of hairpin small RNAs involved in resistance and pathogenesis during wheat-Puccinia triticina interactions.

Wheat leaf rust, caused by the fungus Puccinia triticina (Pt), severely affects the grain quality and quantity of bread wheat (Triticum aestivum L.). Hairpin small(s)RNAs, like micro(mi)RNAs and their variants [including isomiRNAs (isomiRs) and microRNA-like RNAs (milRNAs)], along with their corresponding target genes, bestow leaf rust disease resistance, development and progression from both interacting species. However, the regulatory networks remain inadequately understood. Thirteen differentially expressed novel miRNAs, including two isomiRs and three milRNAs were discerned from induced reads of wheat sRNA libraries, and a further 5,393 and 1,275 candidate target genes were predicted in wheat and Pt, respectively. Functional annotation divulged that wheat-originated miRNAs/isomiRs were involved in resistance, while Pt-derived milRNAs imparted pathogenesis. The identified milRNAs- Tae-Pt-milR5, Tae-Pt-milR12, and Tae-Pt-milR14b and their cleavage sites on Pt target gene MEP5 were confirmed through degradome library screening, suggesting cross-kingdom translocation of Pt virulent genes in wheat host. Co-expression analysis of miRNAs/isomiRs-target genes provided insights into combating leaf rust disease, while co-expression analysis of milRNAs-target gene pairs reflected the extent of pathogenicity exerted by Pt with varied expression levels at the analyzed time points. The analysis pinpointed leaf rust-responsive candidate hairpin sRNAs- Tae-miR8, Tae-Pt-miR12, Tae-Pt-miR14a, and Tae-Pt-miR14b in wheat and Tae-Pt-milR12 in Pt. This study provides new insights into the hairpin sRNAs involved in the resistance and pathogenesis of wheat and Pt, respectively. Furthermore, crucial hairpin sRNAs and their promising targets for future biotechnological interventions to augment stress resilience have been identified.

Expression patterns of candidate genes for the Lr46/Yr29 "slow rust" locus in common wheat (Triticum aestivum L.) and associated miRNAs inform of the gene conferring the Puccinia triticina resistance trait.

Leaf rust caused by Puccinia triticina (Pt) is one of the most impactful diseases causing substantial losses in common wheat (Triticum aestivum L.) crops. In adult plants resistant to Pt, a horizontal adult plant resistance (APR) is observed: APR protects the plant against multiple pathogen races and is distinguished by durable persistence under production conditions. The Lr46/Yr29 locus was mapped to chromosome 1B of common wheat genome, but the identity of the underlying gene has not been demonstrated although several candidate genes have been proposed. This study aimed to analyze the expression of nine candidate genes located at the Lr46/Yr29 locus and their four complementary miRNAs (tae-miR5384-3p, tae-miR9780, tae-miR9775, and tae-miR164), in response to Pt infection. The plant materials tested included five reference cultivars in which the molecular marker csLV46G22 associated with the Lr46/Yr29-based Pt resistance was identified, as well as one susceptible control cultivar. Biotic stress was induced in adult plants by inoculation with fungal spores under controlled conditions. Plant material was sampled before and at 6, 12, 24, 48 hours post inoculation (hpi). Differences in expression of candidate genes at the Lr46/Yr29 locus were analyzed by qRT-PCR and showed that the expression of the genes varied at the analyzed time points. The highest expression of Lr46/Yr29 candidate genes (Lr46-Glu1, Lr46-Glu2, Lr46-Glu3, Lr46-RLK1, Lr46-RLK2, Lr46-RLK3, Lr46-RLK4, Lr46-Snex, and Lr46-WRKY) occurred at 12 and 24 hpi and such expression profiles were obtained only for one candidate gene among the nine genes analyzed (Lr46-Glu2), indicating that it may be a contributing factor in the resistance response to Pt infection.

Identification and functional characterization of the npc-2-like domain containing rust effector protein that suppresses cell death in plants.

The MD-2-related lipid-recognition (ML/Md-2) domain is a lipid/sterol-binding domain that are involved in sterol transfer and innate immunity in eukaryotes. Here we report a genome-wide survey of this family, identifying 84 genes in 30 fungi including plant pathogens. All the studied species were found to have varied ML numbers, and expansion of the family was observed in Rhizophagus irregularis (RI) with 33 genes. The molecular docking studies of these proteins with cholesterol derivatives indicate lipid-binding functional conservation across the animal and fungi kingdom. The phylogenetic studies among eukaryotic ML proteins showed that Puccinia ML members are more closely associated with animal (insect) npc2 proteins than other fungal ML members. One of the candidates from leaf rust fungus Puccinia triticina, Pt5643 was PCR amplified and further characterized using various studies such as qRT-PCR, subcellular localization studies, yeast functional complementation, signal peptide validation, and expression studies. The Pt5643 exhibits the highest expression on the 5th day post-infection (dpi). The confocal microscopy of Pt5643 in onion epidermal cells and N. benthamiana shows its location in the cytoplasm and nucleus. The functional complementation studies of Pt5643 in npc2 mutant yeast showed its functional similarity to the eukaryotic/yeast npc2 gene. Furthermore, the overexpression of Pt5643 also suppressed the BAX, NEP1, and H2O2-induced program cell death in Nicotiana species and yeast. Altogether the present study reports the novel function of ML domain proteins in plant fungal pathogens and their possible role as effector molecules in host defense manipulation.

A multi-view multi-label fast model for Auricularia cornea phenotype identification and classification.

The identification and classification of various phenotypic features of Auricularia cornea fruit bodies are crucial for quality grading and breeding efforts. The phenotypic features of Auricularia cornea fruit bodies encompass size, number, shape, color, pigmentation, and damage. These phenotypic features are distributed across various views of the fruit bodies, making the task of achieving both rapid and accurate identification and classification challenging. This paper proposes a novel multi-view multi-label fast network that integrates two different views of the Auricularia cornea fruiting body, enabling rapid and precise identification and classification of six phenotypic features simultaneously. Initially, a multi-view feature extraction model based on partial convolution was constructed. This model incorporates channel attention mechanisms to achieve rapid phenotypic feature extraction of the Auricularia cornea fruiting body. Subsequently, an efficient multi-task classifier was designed, based on class-specific residual attention, to ensure accurate classification of phenotypic features. Finally, task weights were dynamically adjusted based on heteroscedastic uncertainty, reducing the training complexity of the multi-task classification. The proposed network achieved a classification accuracy of 94.66% and an inference speed of 11.9 ms on an image dataset of dried Auricularia cornea fruiting bodies with three views and six labels. The results demonstrate that the proposed network can efficiently and accurately identify and classify all phenotypic features of Auricularia cornea.

Mapping rust resistance in European winter wheat: many QTLs for yellow rust resistance, but only a few well characterized genes for stem rust resistance.

KEY MESSAGE: Stem rust resistance was mainly based on a few, already known resistance genes; for yellow rust resistance there was a combination of designated genes and minor QTLs. Yellow rust (YR) caused by Puccinia striiformis f. sp. tritici (Pst) and stem rust (SR) caused by Puccinia graminis f. sp. tritici (Pgt) are among the most damaging wheat diseases. Although, yellow rust has occurred regularly in Europe since the advent of the Warrior race in 2011, damaging stem rust epidemics are still unusual. We analyzed the resistance of seven segregating populations at the adult growth stage with the parents being selected for YR and SR resistances across three to six environments (location-year combinations) following inoculation with defined Pst and Pgt races. In total, 600 progenies were phenotyped and 563 were genotyped with a 25k SNP array. For SR resistance, three major resistance genes (Sr24, Sr31, Sr38/Yr17) were detected in different combinations. Additional QTLs provided much smaller effects except for a gene on chromosome 4B that explained much of the genetic variance. For YR resistance, ten loci with highly varying percentages of explained genetic variance (pG, 6-99%) were mapped. Our results imply that introgression of new SR resistances will be necessary for breeding future rust resistant cultivars, whereas YR resistance can be achieved by genomic selection of many of the detected QTLs.

Zearalenone removal using inactivated yeast embedded in porous modified yam starch aerogels and its application in corn silk tea.

Zearalenone contaminates food and poses a threat to human health. It is vital to develop cost-effective and environmentally-friendly adsorbents for its removal. By screening Sporobolomyces pararoseus (SZ4) and modified yam starch (adsorption capacity (qe) of 1.33 and 0.94 mg/g, respectively), this study prepared a novel composite aerogel adsorbent (P-YSA@SZ410). The compressive strength of P-YSA@SZ410 was 1.35-fold higher than unloaded yeast. It contained several functional groups and three-dimensional interconnected channels, achieving a 0° contact angle within 0.18 s, thereby demonstrating excellent water-absorbent properties. With a qe of 2.96 mg/g at 308 K, the adsorption process of P-YSA@SZ410 was spontaneous, endothermic, and matched pseudo-second-order and Langmuir models. The composite adsorbed zearalenone via electrostatic attraction and hydrogen bonding, maintaining a qe of 2.24 mg/g after five cycles. P-YSA@SZ410 was found to remove zearalenone effectively under various conditions and could be applied to corn silk tea, indicating its great potential as an adsorbent material.

Cuttlefish ink-derived melanin nanoparticle-embedded tremella fuciformis polysaccharide hydrogels for the treatment of MRSA-infected diabetic wounds.

Diabetic wounds arise great attention as they are difficult to heal and easily suffer from serious bacterial infection. However, the overuse of antibiotics increases the resistance of bacteria and makes common drugs ineffective. Here, we developed a photothermal hydrogel (TFP/NP) composed of tremella fuciformis polysaccharides (TFPs) and cuttlefish ink-derived melanin nanoparticles (NPs). The NPs can produce reliable photothermal effects under near-infrared laser (NIR) irradiation and help to remove the bacteria in the wounds, while TFPs were able to form hydrogel frameworks which possessed anti-inflammatory effects and could be applied to promote wound healing. The TFP/NP hydrogels produced stable thermal effects under NIR irradiation and could continuously kill bacteria. The experiment on a full-layer skin wound sMRSA activity and could improve the healing efficiency. The wounds of the mice could be repaired within 14 days after reasonable treatment. In addition, the hydrogels play significant roles in promoting collagen deposition, anti-inflammation, angiogenesis, and cell proliferation during the therapeutic process. This research provides a simple and effective method for the therapy of bacterial infection wounds through the synergistic effect of TFPs and NPs.

Fine-mapping of LrN3B on wheat chromosome arm 3BS, one of the two complementary genes for adult-plant leaf rust resistance.

The common wheat line 4N0461 showed adult-plant resistance to leaf rust. 4N0461 was crossed with susceptible cultivars Nongda4503 and Shi4185 to map the causal resistance gene(s). Segregation of leaf rust response in F2 populations from both crosses was 9 resistant:7 susceptible, indicative of two complementary dominant resistance genes. The genes were located on chromosome arms 3BS and 4BL and temporarily named LrN3B and LrN4B, respectively. Subpopulations from 4N0461 × Nongda4503 with LrN3B segregating as a single allele were used to fine-map LrN3B locus. LrN3B was delineated in a genetic interval of 0.07 cM, corresponding to 106 kb based on the Chinese Spring reference genome (IWGSC RefSeq v1.1). Four genes were annotated in this region, among which TraesCS3B02G014800 and TraesCS3B02G014900 differed between resistant and susceptible genotypes, and both were required for LrN3B resistance in virus-induced gene silencing experiments. Diagnostic markers developed for checking the polymorphism of each candidate gene, can be used for marker-assisted selection in wheat breeding programs.

Sequencing, assembly, and genomic annotation of Leucoagaricus gongylophorus LEU18496, a dikarya mutualistic species.

The basidiomycete fungus Leucoagaricus gongylophorus is able to grow in the fungus garden of leaf-cutter ants. This mutualistic interaction has driven the evolutionary adaptation of L. gongylophorus, shaping its metabolism to produce enzymes adept at lignocellulosic biomass degradation. In this study, we undertook the comprehensive sequencing, assembly, and functional annotation of the genome of L. gongylophorus strain LEU18496, mutualistic fungus of the Atta mexicana. Our genomic analyses revealed a distinctive bimodal nature to the genome: a predominant region characterized by AT enrichment and low genetic density, alongside a smaller region exhibiting higher GC content and higher genetic density. The presence of transposable elements (TEs) within the AT-enriched region suggests genomic compartmentalization, facilitating differential evolutionary rates. With a gene count of 6748, the assembled genome of L. gongylophorus LEU18496 surpasses previous reports for this fungal species. Inspection of genes associated with central metabolism unveiled a remarkable abundance of carbohydrate-active enzymes (CAZymes) and fungal oxidative lignin enzymes (FOLymes), underscoring their pivotal roles in the life cycle of this fungus.

The genome sequencing and comparative genomics analysis of Rhizoctonia solani reveals a novel effector family owning a uinque domain in Basidiomycetes.

Rhizoctonia solani is a soil-borne pathogen with 14 anastomosis groups (AGs), and different subgroups are genetically diverse. However, the genetic factors contributing to the pathogenicity of the fungus have not been well characterized. In this study, the genome of R. solani AG1-ZJ was sequenced. As the result, a 41.57 Mb draft genome containing 12,197 putative coding genes was obtained. Comparative genomic analysis of 11 different AGs revealed conservation and unique characteristics between the AGs. Furthermore, a novel effector family containing a 68 amino acid conserved domain unique in basidiomycetous fungi was characterized. Two effectors containing the conserved domain in AG4-JY were identified, and named as RsUEB1 and RsUEB2. Furthermore, the spray-induced gene silencing strategy was used to generate a dsRNA capable of silencing the conserved domain sequence of RsUEB1 and RsUEB2. This dsRNA can significantly reduce the expression of RsUEB1 and RsUEB2 and the pathogenicity of AG4-JY on foxtail millet, maize, rice and wheat. In conclusion, this study provides significant insights into the pathogenicity mechanisms of R. solani. The identification of the conserved domain and the successful use of dsRNA silencing of the gene containing the conserved domain will offer a new strategy for controlling sheath blight in cereal crops.

Identification of stripe rust resistance gene YrBDT in Chinese landrace wheat Baidatou using BSE-seq and BSR-seq.

KEY MESSAGE: A new stripe rust resistance gene YrBDT in Chinese landrace wheat Baidatou was mapped to a 943.6-kb interval on chromosome arm 6DS and co-segregated with a marker CAPS3 developed from candidate gene TraesCS6D03G0027300. Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a devastating foliar disease of wheat. Chinese landrace wheat Baidatou has shown high resistance to a broad spectrum of Pst races at both the seedling and adult-plant stages for decades in the Longnan region of Gansu province, a hot spot for stripe rust epidemics. Here, we report fine mapping and candidate gene analysis of stripe rust resistance gene YrBDT in Baidatou. Analysis of F1, F2 plants and F2:3 lines indicated that resistance in Baidatou to Pst race CYR31 was conferred by a single dominant gene, temporarily designated YrBDT. Bulked segregant exome capture sequencing (BSE-seq) analysis revealed 61 high-confidence polymorphic SNPs concentrated in a 5.4-Mb interval at the distal of chromosome arm 6DS. Several SNPs and InDels were also identified by genome mining of DNA sampled from the parents and contrasting bulks. The YrBDT locus was mapped to a 943.6-kb (4,658,322-5,601,880 bp) genomic region spanned by markers STS2 and STS3 based on IWGSC RefSeq v2.1, including five putative disease resistance genes. There was high collinearity of the target interval among Chinese Spring RefSeq v2.1, Ae. tauschii AL8/78 and Fielder genomes. The expression level of TraesCS6D03G0027300 showed significant association with Pst infection, and a gene-specific marker CAPS3 developed from TraesCS6D03G0027300 co-segregated with YrBDT suggesting this gene as a candidate of YrBDT. The resistance gene and flanking markers can be used in marker-assisted selection for improvement of stripe rust resistance.