Transforming growth factor-ß1 protects against white matter injury and reactive astrogliosis via the p38 MAPK pathway in rodent demyelinating model.

In central nervous system (CNS), demyelination is a pathological process featured with a loss of myelin sheaths around axons, which is responsible for the diseases of multiple sclerosis, neuromyelitis optica, and so on. Transforming growth factor-beta1 (TGF-ß1) is a multifunctional cytokine participating in abundant physiological and pathological processes in CNS. However, the effects of TGF-ß1 on CNS demyelinating disease and its underlying mechanisms are controversial and not well understood. Herein, we evaluated the protective potential of TGF-ß1 in a rodent demyelinating model established by lysophosphatidylcholine (LPC) injection. It was identified that supplement of TGF-ß1 evidently rescued the cognitive deficit and motor dysfunction in LPC modeling mice assessed by novel object recognition and balance beam behavioral tests. Besides, quantified by luxol fast blue staining, immunofluorescence, and western blot, administration of TGF-ß1 was found to significantly ameliorate the demyelinating lesion and reactive astrogliosis by suppressing p38 MAPK pathway. Mechanistically, the results of in vitro experiments indicated that treatment of TGF-ß1 could directly promote the differentiation and migration of cultured oligodendrocytes. Our study revealed that modulating TGF-ß1 activity might serve as a promising and innovative therapeutic strategy in CNS demyelinating diseases.

SYK promotes the formation of neutrophil extracellular traps by inducing PKM2 nuclear translocation and promoting STAT3 phosphorylation to exacerbate hepatic ischemia-reperfusion injury and tumor recurrence.

BACKGROUND: At present, hepatic ischemia-reperfusion injury (IRI) is an important complication of partial hepatectomy and liver transplantation, and it is an important cause of poor prognosis. Spleen tyrosine kinase(SYK) plays an important role in a variety of signaling pathways in the liver, but its role in hepatic IRI is still unclear. This study aims to investigate the role and mechanism of SYK in hepatic IRI and tumor recurrence. METHODS: We first observed the activation of SYK in the liver of mice in response to hepatic IRI. Subsequently, Pharmacological inhibitions of SYK were used to evaluated the effect of SYK on neutrophil recruitment and NETosis, and further explored the effect of SYK on IRI and tumor recurrence. RESULTS: Our study shows that SYK is activated in response to hepatic IRI and aggravates liver injury. On the one hand, neutrophils SYK during the early stage of liver reperfusion increases neutrophil extracellular traps (NETs) production by promoting Pyruvate kinase M2(PKM2) nuclear translocation leading to upregulation of phosphorylated STAT3, thereby exacerbating liver inflammation and tumor recurrence. On the other hand, macrophages SYK can promote the recruitment of neutrophils and increase the activation of NLRP3 inflammasome and IL1ß, which further promotes the formation of NETs. CONCLUSIONS: Our study demonstrates that neutrophil and macrophage SYK synergistically promote hepatic IRI and tumor recurrence, and SYK may be a potential target to improve postoperative hepatic IRI and tumor recurrence.

Astrocyte-Derived Exosomes Contribute to Pathologies of Neuromyelitis Optica Spectrum Disorder in Rodent Model.

OBJECTIVE: Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease that leads to severe disability. A large proportion of NMOSD patients are seropositive for aquaporin-4 autoantibodies (AQP4-IgG, named as NMO-IgG) targeting AQP4, which is selectively expressed on astrocytes in the central nervous system. This study tests the hypothesis that in response to NMO-IgG, the pathogenic astrocyte-derived exosomes are released and injure the neighboring cells. METHODS: IgG purified from serum of either NMOSD patients or healthy controls was used to generate astrocyte-derived exosomes (AST-ExosNMO vs AST-ExosCON ) in cultured rat astrocytes. The exosomes were respectively delivered to cultured rat oligodendrocytes in vitro, tissue culture of rat optic nerve ex vivo, and rat optic nerve in vivo to evaluate the pathogenic roles of AST-ExosNMO . The microRNA (miRNA) sequencing of AST-Exos and verification were performed to identify the key pathogenic miRNA. The custom-designed adeno-associated virus (AAV) antagonizing the key miRNA was evaluated for its therapeutic effects in vivo. Moreover, the serum levels of the key exosomal miRNA were measured between NMOSD patients and healthy controls. RESULTS: AST-ExosNMO led to notable demyelination in both cultured oligodendrocytes and optic nerve tissue. Exosomal miR-129-2-3p was identified as the key miRNA mediating the demyelinating pathogenesis via downstream target gene SMAD3. AAV antagonizing miR-129-2-3p protected against demyelination in an NMOSD rodent model. The serum exosomal miR-129-2-3p level was significantly elevated in NMOSD patients and correlated with disease severity. INTERPRETATION: Astrocytes targeted by NMO-IgG release pathogenic exosomes that could potentially be used as therapeutic targets or disease monitoring biomarkers in NMOSD. ANN NEUROL 2023;94:163-181.

The role of PALLD-STAT3 interaction in megakaryocyte differentiation and thrombocytopenia treatment.

Impaired differentiation of megakaryocytes constitutes the principal etiology of thrombocytopenia. The signal transducer and activator of transcription 3 (STAT3) is a crucial transcription factor in regulating megakaryocyte differentiation, yet the precise mechanism of its activation remains unclear. PALLD, an actin-associated protein, has been increasingly recognized for its essential functions in multiple biological processes. This study revealed that megakaryocyte/plateletspecific knockout of PALLD in mice exhibited thrombocytopenia due to diminished platelet biogenesis. In megakaryocytes, PALLD deficiency led to impaired proplatelet formation and polyploidization, ultimately weakening their differentiation for platelet production. Mechanistic studies demonstrated that PALLD bound to STAT3 and interacted with its DNA-binding domain (DBD) and Src homology 2 (SH2) domain via Immunoglobulin domain 3 (Ig3). Moreover, the absence of PALLD attenuated STAT3 Y705 phosphorylation and impeded STAT3 nuclear translocation. Based on the PALLD-STAT3 binding sequence, we designed a peptide C-P3, which can facilitate megakaryocyte differentiation and accelerate platelet production in vivo. In conclusion, this study highlights the pivotal role of PALLD in megakaryocyte differentiation and proposes a novel approach for treating thrombocytopenia by targeting the PALLD-STAT3 interaction.

Two Mn(II)-Bridged Silverton-Type [UMo12O42]8- Polyoxometalates with Catalytic Activity for the Synthesis of Pyrazoles.

Two Mn(II)-bridged Silverton-type {UMo12O42}-based polyoxomolybdates with different three-dimensional structures, Na6(H2O)12[Mn(UMo12O42)] (NaMn) and (NH4)2[K2Na6(µ4-O)2(H2O)1.2Mn(UMo12O42)]·4.6H2O (KMn), were hydrothermally synthesized and further characterized, demonstrating a feasible strategy for the assembly of Silverton-type polyoxomolybdates. Additionally, NaMn is demonstrated to be a good heterogeneous catalyst in the condensation cyclization reaction of hydrazines and 1,3-diketones, and a range of valuable pyrazoles were produced in up to 99% yield.

Three Polyoxometalate-Based Ag-Organic Compounds as Heterogeneous Catalysts for the Synthesis of Benzimidazoles.

Three new POM-based compounds, with formulae [Na0.63Ag3(Htba)2.37(tba)0.63(H2O)2(PMo12O40)]·4H2O (Ag3PMo), [Ag4(Htba)4(H2O)2(PMo12O40)](NO3)·H2O (Ag4PMo), and [Ag3(Htba)2(tba)(PW12O40)0.5](NO3)0.5·13H2O (Ag3PW), were prepared with a 3-(4H-1,2,4-triazol-4-yl)benzoic acid (Htba) ligand, Keggin-type anions ([PMo12O40]3-/[PW12O40]3-), and a silver ion (Ag+). The structural features of these compounds are particularly different from the multinuclear subunits, which are [Ag3(tba)3] clusters in Ag3PMo, [Ag4(tba)3] chains in Ag4PMo, and [Ag3(tba)3]2 clusters in Ag3PW, connected by multidonor atom tba ligands and Ag+ ions. Meanwhile, in these compounds, polyanions act as polydentate ligands to link adjacent Ag-tba metal-organic units and expand their spatial dimensions. These compounds, as heterogeneous catalysts, exhibit high stability and excellent catalytic activity to construct benzimidazoles. Ag3PMo could efficiently catalyze the condensation of benzene-1,2-diamines and benzaldehydes and produce benzimidazoles in good yields. In addition, Ag3PMo could be reused up to 7 times and was suitable for gram-scale reactions.

Association of longitudinal trajectories of fasting plasma glucose with all-cause and cardiovascular mortality among a Chinese older population: a retrospective cohort study.

The association between fasting plasma glucose (FPG), an important indicator of overall glycemic status, and the risk of cardiovascular mortality has been well investigated. The longitudinal study can repeatedly collect measured results for the variables to be studied and then consider the potential effects of intraindividual changes in measurement. This study aimed to identify long-term FPG trajectories and investigate the association between trajectory groups and cardiovascular and all-cause mortality. A latent class growth mixture modeling (LCGMM) was used to identify FPG trajectories. Cox proportional hazard models were used to estimate associations between FPG trajectories and the risk of all-cause and cardiovascular mortality. A U-shaped relationship between FPG and all-cause and cardiovascular mortality was observed in the restricted cubic spline regression models. Two FPG longitudinal trajectories of low-level (mean FPG = 5.12mmol/L) and high-level (mean FPG = 6.74mmol/L) were identified by LCGMM. After being adjusted for potential confounders, compared with the low-level category, the hazard ratios (HRs) for all-cause and cardiovascular mortality were 1.23(1.16-1.30) and 1.25(1.16-1.35), respectively, for the high-level group. Long-term FPG trajectories are significantly associated with and potentially impact the risk of all-cause and cardiovascular mortality.

Mapping of a Recessive Gene for All-Stage Resistance to Stripe Rust in a Wheat Line Derived from Cultivated Einkorn (Triticum monococcum).

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive fungal diseases of wheat. Cultivated einkorn (Triticum monococcum L. ssp. monococcum, 2n = 2x = 14, AmAm), one of the founder crops of agriculture, harbors unexploited genetic sources for wheat improvement. An advanced wheat line, Z15-1949, with 42 chromosomes, selected from the hybrids of Pst-susceptible common wheat cultivar Crocus and resistant T. monococcum accession 10-1, exhibits high resistance to a mixture of the prevalent Chinese Pst races. Genetic analysis on F1, F2, and F2:3 generations of the cross between Z15-1949 and Pst-susceptible common wheat SY95-71 indicated that the resistance of Z15-1949 was conferred by a recessive gene, tentatively designated as YrZ15-1949. This gene was mapped to the short arm of chromosome 7D using the Wheat 55K single nucleotide polymorphism array, flanked by markers KASP-1949-2 and KASP-1949-10 within a 3.3-cM genetic interval corresponding to a 1.12-Mb physical region in the Chinese Spring reference genome V2.0. The gene differs from previously reported Yr genes on 7D based on their physical positions and is probably a novel gene. YrZ15-1949 would be a valuable resource for developing Pst-resistant wheat cultivars, and the linked markers could be used for marker-assisted selection.

Explainable Deep Learning-Based Feature Selection and Intrusion Detection Method on the Internet of Things.

With the rapid advancement of the Internet of Things, network security has garnered increasing attention from researchers. Applying deep learning (DL) has significantly enhanced the performance of Network Intrusion Detection Systems (NIDSs). However, due to its complexity and "black box" problem, deploying DL-based NIDS models in practical scenarios poses several challenges, including model interpretability and being lightweight. Feature selection (FS) in DL models plays a crucial role in minimizing model parameters and decreasing computational overheads while enhancing NIDS performance. Hence, selecting effective features remains a pivotal concern for NIDSs. In light of this, this paper proposes an interpretable feature selection method for encrypted traffic intrusion detection based on SHAP and causality principles. This approach utilizes the results of model interpretation for feature selection to reduce feature count while ensuring model reliability. We evaluate and validate our proposed method on two public network traffic datasets, CICIDS2017 and NSL-KDD, employing both a CNN and a random forest (RF). Experimental results demonstrate superior performance achieved by our proposed method.

Development of an LFD-RPA Assay for Rapid Detection of Pentatrichomonas hominis Infection in Dogs.

Pentatrichomonas hominis is a trichomonad protozoan that infects the cecum and colon of humans and other mammals. It is a zoonotic pathogen that causes diarrhea in both animals and humans. As companion animals, dogs infected with P. hominis pose a risk of transmitting it to humans. Current methods, such as direct smears and polymerase chain reaction (PCR), used for P. hominis detection have limitations, including low detection rates and the need for specialized equipment. Therefore, there is an urgent need to develop rapid, sensitive, and simple detection methods for clinical application. Recombinase polymerase amplification (RPA) has emerged as a technology for rapid pathogen detection. In this study, we developed a lateral flow dipstick (LFD)-RPA method based on the highly conserved SPO11-1 gene for detecting P. hominis infection by optimizing the primers, probes, and reaction conditions, and evaluating cross-reactivity with genomes of Giardia duodenalis and other parasites. The LFD-RPA method was then used to test 128 dog fecal samples collected from Changchun. The results confirmed the high specificity of the method with no cross-reactivity with the five other parasites. The lowest detection limit of the method was 102 copies/µL, and its sensitivity was 100 times higher than that of the conventional PCR method. Consistent with the positivity rate observed using nested PCR, 12 samples (out of 128) tested positive using this method (positivity rate, 9.38%). In conclusion, the LFD-RPA method developed in this study represents a simple and sensitive assay that allows for the rapid detection of P. hominis infection in dogs, especially in this field.

Transcriptomic analysis provides insight into the genetic regulation of shade avoidance in Aegilops tauschii.

BACKGROUND: Weeds are not only economically important but also fascinating models for studying the adaptation of species in human-mediated environments. Aegilops tauschii is the D-genome donor species of common wheat but is also a weed that influences wheat production. How shading stress caused by adjacent wheat plants affects Ae. tauschii growth is a fundamental scientific question but is also important in agriculture, such as for weed control and wheat breeding. RESULT: The present study indicated that shade avoidance is a strategy of Ae. tauschii in response to shading stress. Ae. tauschii plants exhibited growth increases in specific organs, such as stem and leaf elongation, to avoid shading. However, these changes were accompanied by sacrificing the growth of other parts of the plants, such as a reduction in tiller number. The two reverse phenotype responses seem to be formed by systemically regulating the expression of different genes. Fifty-six genes involved in the regulation of cell division and cell expansion were found to be downregulated, and one key upstream negative regulator (RPK2) of cell division was upregulated under shading stress. On the other hand, the upregulated genes under shading stress were mainly enriched in protein serine/threonine kinase activity and carbon metabolism, which are associated with cell enlargement, signal transduction and energy supply. The transcription factor WRKY72 may be important in regulating genes in response to shading stress, which can be used as a prior candidate gene for further study on the genetic regulation of shade avoidance. CONCLUSIONS: This study sheds new light on the gene expression changes and molecular processes involved in the response and avoidance of Ae. tauschii to shading stress, which may aid more effective development of shading stress avoidance or cultivars in wheat and other crops in the future.

Hepatocyte SGK1 activated by hepatic ischemia-reperfusion promotes the recurrence of liver metastasis via IL-6/STAT3.

BACKGROUND: Liver metastasis is the leading cause of death in patients with colorectal cancer (CRC). Surgical resection of the liver metastases increases the incidence of long-term survival in patients with colorectal liver metastasis (CRLM). However, many patients experience CRLM recurrence after the initial liver resection. As an unavoidable pathophysiological process in liver surgery, liver ischemia-reperfusion (IR) injury increases the risk of tumor recurrence and metastasis. METHODS: Colorectal liver metastasis (CRLM) mouse models and mouse liver partial warm ischemia models were constructed. The levels of lipid peroxidation were detected in cells or tissues. Western Blot, qPCR, elisa, immunofluorescence, immunohistochemistry, scanning electron microscope, flow cytometry analysis were conducted to evaluate the changes of multiple signaling pathways during CRLM recurrence under liver ischemia-reperfusion (IR) background, including SGK1/IL-6/STAT3, neutrophil extracellular traps (NETs) formation, polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) infiltration. RESULTS: Hepatocyte serum/glucocorticoid regulated kinase 1 (SGK1) was activated in response to hepatic ischemia-reperfusion injury to pass hepatocyte STAT3 phosphorylation and serum amyloid A (SAA) hyperactivation signals in CRLM-IR mice, such regulation is dependent on SGK-activated IL-6 autocrine. Administration of the SGK1 inhibitor GSK-650394 further reduced ERK-related neutrophil extracellular traps (NETs) formation and polymorphonucler myeloid-derived suppressor cells (PMN-MDSC) infiltration compared with targeting hepatocyte SGK1 alone, thereby alleviating CRLM in the context of IR. CONCLUSIONS: Our study demonstrates that hepatocyte and immune cell SGK1 synergistically promote postoperative CRLM recurrence in response to hepatic IR stress, and identifies SGK1 as a translational target that may improve postoperative CRLM recurrence.

Identification and fine-mapping of QYrAS286-2BL conferring adult-plant resistance to stripe rust in cultivated emmer wheat.

KEY MESSAGE: A novel major adult-plant stripe rust resistance QTL derived from cultivated emmer wheat was mapped to a 123.6-kb region on wheat chromosome 2BL. Stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat. Identification of new sources of resistance and their utilization in breeding programs is the effectively control strategy. The objective of this study was to identify and genetically characterize the stripe rust resistance derived from the cultivated emmer accession AS286. A recombinant inbred line population, developed from a cross between the susceptible durum wheat line langdon and AS286, was genotyped using the Wheat55K single nucleotide polymorphism array and evaluated in field conditions with a mixture of the prevalent Chinese Pst races (CYR32, CYR33, CYR34, Zhong4, and HY46) and in growth chamber with race CYR34. Three QTLs conferring resistance were mapped on chromosomes 1BS, 2BL, and 5BL, respectively. The QYrAS286-1BS and QYrAS286-2BL were stable with major effects, explaining 12.91% to 18.82% and 11.31% to 31.43% of phenotypic variation, respectively. QYrAS286-5BL was only detected based on growth chamber seedling data. RILs harboring both QYrAS286-1BS and QYrAS286-2BL showed high levels of stripe rust resistance equal to the parent AS286. The QYrAS286-2BL was only detected at the adult-plant stage, which is different from previously named Yr genes and inherited as a single gene. It was further mapped to a 123.6-kb region using KASP markers derived from SNPs identified by bulked segregant RNA sequencing (BSR-Seq). The identified loci enrich our stripe rust resistance gene pool, and the flanking markers developed here could be useful in marker-assisted selection for incorporating QYrAS286-2BL into wheat cultivars.

Relationship between obesity indicators and hypertension-diabetes comorbidity in an elderly population: a retrospective cohort study.

BACKGROUND: The prevalence of obesity, hypertension and diabetes is increasing. Hypertension and diabetes are common complications. Additionally, obesity and hypertension-diabetes comorbidity (HDC) are both closely related to insulin resistance. The aim of this study was to determine the association of obesity indicators with HDC in elderly individuals. METHODS: This retrospective cohort study included 74,955 subjects aged ≥ 60 years living in Xinzheng, Henan Province, from January 2011 to December 2019. The data were collected from the annual health examination dataset. Cox proportional hazard regression models and competing-risk survival regression models were used to examine the relationships between the three indicators and HDC risk. RESULTS: After 346,504 person-years of follow-up, HDC developed in 9,647 subjects. After further adjustments for confounders and death competing risks, compared with a body mass index (BMI) of 18.5-23.9 kg/m2, the fully adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of BMI < 18.5, 24-27.9 and ≥ 28 kg/m2 for HDC morbidity were 0.651(0.538,0.788),1.00,1.396(1.336,1.459) and 1.769(1.666,1.878), respectively. Moreover, participants with abdominal obesity measured via waist circumference (WC) or waist-to-height ratio (WtHR) had a higher risk of HDC (HR:1.513; 95% CI: 1.45,1.578 and HR:1.412;95% CI: 1.353,1.473), respectively, than participants with low WC or with low WtHR. In the joint analyses, the highest risk was observed in participants who were overweight and who had central obesity (HR: 1.721; 95% CI: 1.635, 1.811) compared with the nonoverweight and noncentral obesity groups. CONCLUSIONS: Increased BMI, WC and WtHR were associated with an increased risk of HDC. There was an additive interaction between general body adiposity (as measured via BMI) and central obesity (as measured via WC and WtHR) for HDC. Therefore, reasonable control of BMI, WC and WtHR may be an effective measure to prevent HDC among elderly individuals.

The construction and operational models of internet hospitals in China: a hospital-based survey study.

BACKGROUND: China has empowered and continues to empower internet hospitals, which saw an increase in their development due to the pandemic, to fight against COVID-19. The construction and operational models of internet hospitals can be categorized as self-constructed and self-managed models, self-constructed and enterprise-run models, hospital and enterprise joint-owned models, and hosted by a third-party platform. Despite the growing importance of internet hospitals, there have been few systematic summaries of their construction and operational models. The primary purpose of the study was to understand the construction and operational models of internet hospitals in China. METHODS: Data was collected from 39 internet hospitals and 356 medical staff between September 2020 and April 2021, via internet hospital and hospital staff surveys. T-tests were used to compare the continuous variables, while Chi-square tests were employed to compare the proportions of categorical variables. The self-perception of the internet hospitals' services was assessed using a 5-point Likert scale on 16 aspects and a root cause analysis was conducted to identify the root causes and influencing factors of current deficiencies experienced by internet hospitals. RESULTS: Among the 39 internet hospitals, 22 (56.4%) were self-constructed and self-managed. Compared to other models of Internet hospitals, self-constructed and self-managed hospitals had lower percentages of professionals providing online services (P = 0.006), numbers of doctors outside of the entity (P = 0.006), numbers of online nurses (P = 0.004), and the ratio of online nurses to offline doctors (P < 0.001). Of the 16 aspects evaluated with regards to the medical staff's self-perception of the internet hospital services, the highest scores were given for fee transparency, fee rationality, travel cost capital, patience and responsibility, and consultation behaviors. The root causes included five aspects: human, channels, prices, services, and time. CONCLUSIONS: While the self-constructed and self-managed model was found to be the most prevalent form of internet hospital in China, the different models of internet hospitals can have an impact on both the quantity and quality of online healthcare services. This study contributes to the existing literature on internet hospitals' construction and operational models, offering additional policy implications for telemedicine management.

Graphene oxide affected root growth, anatomy, and nutrient uptake in alfalfa.

The increasing application of carbon nanomaterials has resulted in their inevitable release into the environment. Their toxic effects on plant roots require careful investigation. In the present study, alfalfa (Medicago sativa L.) was exposed to graphene oxide (GO) at levels of 0.2 %, 0.4 %, and 0.6 % (w/w) in potting soil. This study aims to better understand the impact of GO on the root growth, structure, and physiology of alfalfa in the soil matrix. The results demonstrated that GO significantly affected the development and structure of alfalfa roots, and the effect varied with GO level. The highest level of GO (0.6 %) reduced the root length, diameter, volume, dry weight, number of lateral roots, and root activity by 36.1 %, 31.3 %, 60.0 %, 89.6 %, 55.8 %, and 72.3 % (p < 0.05), respectively, and the vascular cylinder diameter, periderm thickness, vessel diameter, and phellem thickness decreased by 51.5 %, 50.7 %, 80.9 %, and 49.1 % (p < 0.05), respectively. These observations might be associated with GO-induced oxidative stress, which was indicated by the activity of antioxidant enzymes. Furthermore, high GO levels (0.4 % and 0.6 %) inhibited the uptake of N, P, K, Mg, Zn, Fe, Mo, Si, and B in roots. Our findings indicate that GO at high levels has a negative impact on root growth and development by inducing oxidative stress, structural impairment, and nutritional imbalance. Careful soil GO management should be emphasized.

Cytogenetic Characterization and Molecular Marker Development for a Wheat-T. boeoticum 4Ab (4B) Disomic Substitution Line with Stripe Rust Resistance.

Triticum boeoticum (2n = 2x = 14, AbAb) is an important relative of wheat. This species tolerates many different types of environmental stresses, including drought, salt, and pathogenic infection, and is lower in dietary fiber and higher in antioxidants, protein (15 to 18%), lipids, and trace elements than common wheat. However, the gene transfer rate from this species to common wheat is low, and few species-specific molecular markers are available. In this study, the wheat-T. boeoticum substitution line Z1889, derived from a cross between the common wheat cultivar Crocus and T. boeoticum line G52, was identified using multicolor fluorescence in situ hybridization, multicolor genomic in situ hybridization, and a 55K single-nucleotide polymorphism array. Z1889 was revealed to be a 4Ab (4B) substitution line with a high degree of resistance to stripe rust pathogen strains prevalent in China. In addition, 22 4Ab chromosome-specific molecular markers and 11 T. boeoticum genome-specific molecular markers were developed from 1,145 4Ab chromosome-specific fragments by comparing the sequences generated by specific-length amplified fragment sequencing, with an efficiency of up to 55.0%. Furthermore, the specificity of these markers was verified in four species containing the Ab genome. These markers not only can be used for the detection of the 4Ab chromosome but also provide a basis for molecular marker-assisted, selection-based breeding in wheat.

Pyramiding of Adult-Plant Resistance Genes Enhances All-Stage Resistance to Wheat Stripe Rust.

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive diseases in wheat production. Pyramiding of adult-plant resistance (APR) genes is a promising strategy to increase durability of resistance. The stripe rust resistance (R) genes Yr18, Yr28, and Yr36 encode different protein families which confer partial resistance to a broad array of P. striiformis f. sp. tritici races. Here, we developed BC3F5 wheat lines representing all possible combinations of Yr18, Yr28, and Yr36 in a genetic background of the highly P. striiformis f. sp. tritici-susceptible wheat line SY95-71 that is widely used in stripe rust analysis. These lines enabled us to accurately evaluate these genes singly and in combination in a common genetic background. The adult plant resistance experiments were analyzed in the field, where stripe rust epidemics occurred frequently. The field results indicated that these partial R genes act additively in enhancing the levels of resistance, and a minimum of two-gene combinations can generate adequate stripe rust resistance. The Yr28 + Yr36 and Yr18 + Yr28 + Yr36 combinations also showed adequate resistance at the seedling stage, implying that APR gene pyramiding can achieve all-stage resistance. Meanwhile, the three genes were simultaneously introduced into elite wheat lines through gene-based marker selection. Elite lines exhibited strong all-stage resistance to stripe rust. This work provides valuable insights and resources for developing durable P. striiformis f. sp. tritici-resistant varieties and for elucidating the regulation mechanism of partial R gene pyramiding.

Development and Characterization of Near-Isogenic Lines Derived from Synthetic Wheat Revealing the 2 kb Insertion in the PPD-D1 Gene Responsible for Heading Delay and Grain Number Improvement.

Spikelet number and grain number per spike are two crucial and correlated traits for grain yield in wheat. Photoperiod-1 (Ppd-1) is a key regulator of inflorescence architecture and spikelet formation in wheat. In this study, near-isogenic lines derived from the cross of a synthetic hexaploid wheat and commercial cultivars generated by double top-cross and two-phase selection were evaluated for the number of days to heading and other agronomic traits. The results showed that heading time segregation was conferred by a single incomplete dominant gene PPD-D1, and the 2 kb insertion in the promoter region was responsible for the delay in heading. Meanwhile, slightly delayed heading plants and later heading plants obviously have advantages in grain number and spikelet number of the main spike compared with early heading plants. Utilization of PPD-D1 photoperiod sensitivity phenotype as a potential means to increase wheat yield potential.

Identification of the Solid Stem Suppressor Gene Su-TdDof in Synthetic Hexaploid Wheat Syn-SAU-117.

Lodging is one of the most important factors affecting the high and stable yield of wheat worldwide. Solid-stemmed wheat has higher stem strength and lodging resistance than hollow-stemmed wheat does. There are many solid-stemmed varieties, landraces, and old varieties of durum wheat. However, the transfer of solid stem genes from durum wheat is suppressed by a suppressor gene located on chromosome 3D in common wheat, and only hollow-stemmed lines have been created. However, synthetic hexaploid wheat can serve as a bridge for transferring solid stem genes from tetraploid wheat to common wheat. In this study, the F1, F2, and F2:3 generations of a cross between solid-stemmed Syn-SAU-119 and semisolid-stemmed Syn-SAU-117 were developed. A single dominant gene, which was tentatively designated Su-TdDof and suppresses stem solidity, was identified in synthetic hexaploid wheat Syn-SAU-117 by using genetic analysis. By using bulked segregant RNA-seq (BSR-seq) analysis, Su-TdDof was mapped to chromosome 7DS and flanked by markers KASP-669 and KASP-1055 within a 4.53 cM genetic interval corresponding to 3.86 Mb and 2.29 Mb physical regions in the Chinese Spring (IWGSC RefSeq v1.1) and Ae. tauschii (AL8/78 v4.0) genomes, respectively, in which three genes related to solid stem development were annotated. Su-TdDof differed from a previously reported solid stem suppressor gene based on its origin and position. Su-TdDof would provide a valuable example for research on the suppression phenomenon. The flanking markers developed in this study might be useful for screening Ae. tauschii accessions with no suppressor gene (Su-TdDof) to develop more synthetic hexaploid wheat lines for the breeding of lodging resistance in wheat and further cloning the suppressor gene Su-TdDof.