Effect of H2O2-VC degradation on structural characteristics and immunomodulatory activity of larch arabinogalactan.

The arabinogalactan in the representative softwood biomass of larch was degraded using an environmentally friendly hydrogen peroxide and vitamin C (H2O2-VC) system to improve its immunomodulatory activity. Through the H2O2-VC degradation mechanism, hydroxyl radicals are generated, which then target the hydrogen atoms within polysaccharides, resulting in the breaking of glycosidic bonds. Given the impact of oxidative degradation on polysaccharides, we identified three specific arabinogalactan degradation products distinguished by their arabinosyl side chain compositions. The primary structures of the degradation products were investigated using Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. Congo red staining showed that the degradation products were absent in the triple-helix structure. The results of the in vitro immunological experiments indicated that an appropriate reduction in the molar ratio of arabinose to galactose enhanced the immunostimulatory effects on RAW 264.7 cells. In addition, the immunostimulatory pathway mediated by arabinogalactan was explored by toll-like receptor 4 (TLR4) inhibitor (TAK-242) These findings provide novel insights into the understanding of the relationship between the structure of arabinogalactan and its biological activity.

Botulinum toxin type A injection combined with biofeedback in the treatment of spastic pelvic floor syndrome.

BACKGROUND: Spastic pelvic floor syndrome (SPFS) is a refractory pelvic floor disease characterized by abnormal (uncoordinated) contractions of the external anal sphincter and puborectalis muscle during defecation, resulting in rectal emptation and obstructive constipation. The clinical manifestations of SPFS are mainly characterized by difficult defecation, often accompanied by a sense of anal blockage and drooping. Manual defecation is usually needed during defecation. From physical examination, it is commonly observed that the patient's anal muscle tension is high, and it is difficult or even impossible to enter with his fingers. AIM: To investigate the characteristics of anorectal pressure and botulinum toxin A injection combined with biofeedback in treating pelvic floor muscle spasm syndrome. METHODS: Retrospective analysis of 50 patients diagnosed with pelvic floor spasm syndrome. All patients underwent pelvic floor surface electromyography assessment, anorectal dynamics examination, botulinum toxin type A injection 100 U intramuscular injection, and two cycles of biofeedback therapy. RESULTS: After the botulinum toxin A injection combined with two cycles of biofeedback therapy, the patient's postoperative resting and systolic blood pressure were significantly lower than before surgery (P < 0.05). Moreover, the electromyography index of the patients in the resting stage and post-resting stages was significantly lower than before surgery (P < 0.05). CONCLUSION: Botulinum toxin A injection combined with biofeedback can significantly reduce pelvic floor muscle tension in treating pelvic floor muscle spasm syndrome. Anorectal manometry is an effective method to evaluate the efficacy of treatment objectively. However, randomized controlled trials are needed.

Structure-dependent destructive adsorption of organophosphate flame retardants on lipid membranes.

The widespread use of organophosphate flame retardants (OPFRs), a serious type of pervasive environmental contaminants, has led to a global concern regarding their diverse toxicities to living beings. Using a combination of experimental and theoretical approaches, we systematically studied the adsorption, accumulation, and influence of a series of OPFRs on the lipid membranes of bacteria and cells. Our results revealed that OPFRs can aggregate in lipid membranes, leading to the destruction of membrane integrity. During this process, the molecular structure of the OPFRs is a dominant factor that significantly influences the strength of their interaction with the lipid membrane, resulting in varying degrees of biotoxicity. Triphenyl phosphate (TPHP), owing to its large molecular size and strong hydrophobicity, causes severe membrane disruption through the formation of nanoclusters. The corresponding severe toxicity originates from the phase transitions of the lipid membranes. In contrast, smaller OPFRs such as triethyl phosphate (TEP) and tris(2-chloroethyl) phosphate (TCEP) have weaker hydrophobicity and induce minimal membrane disturbance and ineffective damage. In vivo, gavage of TPHP induced more severe barrier damage and inflammatory infiltration in mice than TEP or TCEP, confirming the higher toxicity of TPHP. Overall, our study elucidates the structure-dependent adsorption of OPFRs onto lipid membranes, highlighting their destructive interactions with membranes as the origin of OPFR toxicity.

Assessment of Left Atrial Fibrosis by Cardiac Magnetic Resonance Imaging in Ischemic Stroke Patients Without Atrial Fibrillation: A Systematic Review and Meta-Analysis.

BACKGROUND: Left atrial (LA) fibrosis is a marker of atrial cardiomyopathy and has been reported to be associated with both atrial fibrillation and ischemic stroke. Elucidating this relationship is clinically important as LA fibrosis could serve as a surrogate biomarker of LA cardiomyopathy. The objective of this study is to investigate the association of LA fibrosis and embolic stroke of undetermined source (ESUS) using cardiac magnetic resonance imaging. METHODS AND RESULTS: Following an International Prospective Register of Systematic Reviews-registered protocol, 3 blinded reviewers performed a systematic review for studies that quantified the degree of LA fibrosis in patients with ESUS as compared with healthy patients from inception to February 2024. A meta-analysis was conducted in the mean difference. From 7 studies (705 patients), there was a significantly higher degree of LA fibrosis in patients with ESUS compared with healthy controls (MD, 5.71% [95% CI, 3.55%-7.87%], P<0.01). The degree of LA fibrosis was significantly higher in patients with atrial fibrillation than healthy controls (MD, 8.22% [95% CI, 5.62%-10.83%], P<0.01). A similar degree of LA fibrosis was observed in patients with ESUS compared with patients with atrial fibrillation (MD, -0.92% [95% CI, -2.29% to 0.44%], P=0.35). CONCLUSIONS: A significantly higher degree of LA fibrosis was found in patients with ESUS as compared with healthy controls. This suggests that LA fibrosis may play a significant role in the pathogenesis of ESUS. Further research is warranted to investigate LA fibrosis as a surrogate biomarker of atrial cardiomyopathy and recurrent stroke risk in patients with ESUS.

Laparoscopic Surgery for Superior Mesenteric Artery Syndrome.

BACKGROUND: Superior mesenteric artery syndrome (SMAS) is a rare condition, for which laparoscopic surgery was successfully performed safely and with long-term efficacy. METHODS: This single center retrospective clinical study comprised 66 patients with SMAS, surgically treated between January 2010 and January 2020, who were allocated to three different surgical groups according to their medical history and symptoms (Laparoscopic duodenojejunostomy, n = 35; Gastrojejunostomy, n = 16; Duodenojejunostomy plus gastrojejunostomy, n = 15). Patient demographics, surgical data and postoperative outcomes were retrieved from the medical records. RESULTS: All operations were successfully completed laparoscopically, and with a median follow-up of 65 months, the overall symptom score was significantly reduced from 32 to 8 (p < 0.0001) and the BMI was increased from 17.2 kg/m2 to 21.8 kg/m2 (p < 0.0001). CONCLUSIONS: When conservative measures failed in the treatment of SMAS, laparoscopic surgery proved to be a safe and effective method. The specific surgical technique was selected according to the history and symptoms of each individual patient. To our knowledge, this study represents the largest number of laparoscopic procedures at a single center for the treatment of superior mesenteric artery syndrome.

Organo-cation catalyzed enantioselective α-hydroxylation of pyridinone-fused lactones: asymmetric synthesis of SN-38 and irinotecan.

A catalytic asymmetric α-hydroxylation of pyridinone-fused lactones, containing the core structure of camptothecin, is described. Development of a novel spiropyrrolidine amide (SPA) derived triazolium bromide organo-cation catalyst is crucial for a highly enantioselective oxidation, which also accommodates a wide array of lactones with various substituents. The resulting tricyclic tertiary alcohol with an oxa-quaternary carbon center can be further applied in the synthesis of SN-38 and irinotecan, two anti-cancer drugs derived from camptothecin.

B-site substitution effects on the mechanical properties of halide perovskites [C4H12N2][BCl3]·H2O (B = NH4+; K+).

The mechanical properties of halide perovskites have been attracting ever-increasing interest for their significant importance in future industrial applications. However, studies focused on the effect of B-site substitution of molecular perovskites on their mechanical properties are rare, which makes it favorable to shed light on their fundamental structure-mechanical property relationships. Here, using isostructural halide perovskites, [C4H12N2][BCl3]·H2O (B = NH4+; K+), constructed by ionic bonds and hydrogen bonds, respectively, as the model systems, we investigate their mechanical properties through high-pressure synchrotron X-ray diffraction experiments and density functional theory calculations. Owing to the similar sizes of NH4+ and K+, the two compounds possess almost identical cell parameters and frameworks. Upon compression, the two perovskites exhibit analogous behavior except for slight differences in the shrinkage ratio of principal axes and the onset pressure of amorphization. The fitted bulk moduli of [C4H12N2][KCl3]·H2O and [C4H12N2][NH4Cl3]·H2O are 43.89 and 27.28 GPa, respectively. These results demonstrate that the simple replacement of K+ by NH4+ can significantly reduce the structural rigidity of the corresponding compounds, which is ascribed to the weaker strength of NH4⋯Cl hydrogen bonds than that of K-Cl bonds.

[Selection of placement position of support points for early and mid-term mechanical repair of femoral head necrosis].

OBJECTIVE: To investigate the clinical efficacy of the placement of the main mechanical support points in the early and middle stages of mechanical repair of femoral head necrosis in preventing collapse of the femoral head. METHODS: A retrospective analysis was performed for 17 cases 22 hips of non-traumatic femoral head necrosis in the early and middle stages from June 2018 to June 2019, including 14 males 18 hips and 3 females 4 hips, aged 34 to 47 years old. Among them, 6 cases were hormonal, 8 were alcoholic and 3 were idiopathic. According to China-Japan Friendship Hospital(CJFH) classification, 9 hip were type L1, 8 were L2, 5 were L3. All cases were given dead bone scraping, autologous iliac granules pressed bone grafting, and allogeneic fibula column support treatment. After surgery, Sanqi Jiegu Pill() was administered orally for 3 months. X-rays of both hips were performed after surgery and follow-up, and the clinical efficacy was evaluated by hip Harris score before and after surgery. RESULTS: All cases were followed up for 24 to 38 months. The Harris score of 22 hips increased from 58 to 77 preoperative to 68 to 94 at the final follow-up. At the final follow-up, 3 hips were excellent, 11 hips were good, 3 hips were acceptable, 5 hips were poor. Two hips of L2 type progressed to ARCO ⅢB stage and continued to be observed, 2 hips of L2 type and 2 hips of L3 type progressed to ARCO Ⅳ stage, and received total hip replacement, and 1 hip infection at 3 months after surgery was given a cement spacer. CONCLUSION: Based on CJFH classification, collapse can be predicted to a certain extent according to the area, volume, location and human biological characteristics of osteonecrosis, and the main mechanical support points are found on this basis to prevent collapse.

Activation of GPR30 Ameliorates Cerebral Ischemia-Reperfusion Injury by Suppressing Ferroptosis Through Nrf2/GPX4 Signaling Pathway.

The newly identified estrogen receptor, G protein-coupled receptor 30 (GPR30), is prevalent in the brain and has been shown to provide significant neuroprotection. Recent studies have linked ferroptosis, a newly characterized form of programmed cell death, closely with cerebral ischemia-reperfusion injury (CIRI), highlighting it as a major contributing factor. Consequently, our research aimed to explore the potential of GPR30 targeting in controlling neuronal ferroptosis and lessening CIRI impacts. Results indicated that GPR30 activation not only improved neurological outcomes and decreased infarct size in a mouse model but also lessened iron accumulation and malondialdehyde formation post-middle cerebral artery occlusion (MCAO). This protective effect extended to increased levels of Nrf2 and GPX4 proteins. Similar protective results were replicated in PC12 cells subjected to Oxygen Glucose Deprivation and Reoxygenation (OGD/R) using the GPR30-specific agonist G1. Importantly, inhibition of Nrf2 with ML385 curtailed the neuroprotective effects of GPR30 activation, suggesting that GPR30 mitigates CIRI primarily through inhibition of neuronal ferroptosis via upregulation of Nrf2 and GPX4.

Fully Flexible Molecular Alignment Enables Accurate Ligand Structure Modeling.

Accurate protein-ligand binding poses are the prerequisites of structure-based binding affinity prediction and provide the structural basis for in-depth lead optimization in small molecule drug design. However, it is challenging to provide reasonable predictions of binding poses for different molecules due to the complexity and diversity of the chemical space of small molecules. Similarity-based molecular alignment techniques can effectively narrow the search range, as structurally similar molecules are likely to have similar binding modes, with higher similarity usually correlated to higher success rates. However, molecular similarity is not consistently high because molecules often require changes to achieve specific purposes, leading to reduced alignment precision. To address this issue, we propose a new alignment method─Z-align. This method uses topological structural information as a criterion for evaluating similarity, reducing the reliance on molecular fingerprint similarity. Our method has achieved success rates significantly higher than those of other methods at moderate levels of similarity. Additionally, our approach can comprehensively and flexibly optimize bond lengths and angles of molecules, maintaining a high accuracy even when dealing with larger molecules. Consequently, our proposed solution helps in achieving more accurate binding poses in protein-ligand docking problems, facilitating the development of small molecule drugs. Z-align is freely available as a web server at https://cloud.zelixir.com/zalign/home.

Association mapping of tan spot and septoria nodorum blotch resistance in cultivated emmer wheat.

KEY MESSAGE: A total of 65 SNPs associated with resistance to tan spot and septoria nodorum blotch were identified in a panel of 180 cultivated emmer accessions through association mapping Tan spot and septoria nodorum blotch (SNB) are foliar diseases caused by the respective fungal pathogens Pyrenophora tritici-repentis and Parastagonospora nodorum that affect global wheat production. To find new sources of resistance, we evaluated a panel of 180 cultivated emmer wheat (Triticum turgidum ssp. dicoccum) accessions for reactions to four P. tritici-repentis isolates Pti2, 86-124, 331-9 and DW5, two P. nodorum isolate, Sn4 and Sn2000, and four necrotrophic effectors (NEs) produced by the pathogens. About 8-36% of the accessions exhibited resistance to the four P. tritici-repentis isolates, with five accessions demonstrating resistance to all isolates. For SNB, 64% accessions showed resistance to Sn4, 43% to Sn2000 and 36% to both isolates, with Spain (11% accessions) as the most common origin of resistance. To understand the genetic basis of resistance, association mapping was performed using SNP (single nucleotide polymorphism) markers generated by genotype-by-sequencing and the 9 K SNP Infinium array. A total of 46 SNPs were significantly associated with tan spot and 19 SNPs with SNB resistance or susceptibility. Six trait loci on chromosome arms 1BL, 3BL, 4AL (2), 6BL and 7AL conferred resistance to two or more isolates. Known NE sensitivity genes for disease development were undetected except Snn5 for Sn2000, suggesting novel genetic factors are controlling host-pathogen interaction in cultivated emmer. The emmer accessions with the highest levels of resistance to the six pathogen isolates (e.g., CItr 14133-1, PI 94634-1 and PI 377672) could serve as donors for tan spot and SNB resistance in wheat breeding programs.

Value of fractional-order calculus (FROC) model diffusion-weighted imaging combined with simultaneous multi-slice (SMS) acceleration technology for evaluating benign and malignant breast lesions.

BACKGROUND: This study explores the diagnostic value of combining fractional-order calculus (FROC) diffusion-weighted model with simultaneous multi-slice (SMS) acceleration technology in distinguishing benign and malignant breast lesions. METHODS: 178 lesions (73 benign, 105 malignant) underwent magnetic resonance imaging with diffusion-weighted imaging using multiple b-values (14 b-values, highest 3000 s/mm2). Independent samples t-test or Mann-Whitney U test compared image quality scores, FROC model parameters (D,, ), and ADC values between two groups. Multivariate logistic regression analysis identified independent variables and constructed nomograms. Model discrimination ability was assessed with receiver operating characteristic (ROC) curve and calibration chart. Spearman correlation analysis and Bland-Altman plot evaluated parameter correlation and consistency. RESULTS: Malignant lesions exhibited lower D, and ADC values than benign lesions (P < 0.05), with higher values (P < 0.05). In SSEPI-DWI and SMS-SSEPI-DWI sequences, the AUC and diagnostic accuracy of D value are maximal, with D value demonstrating the highest diagnostic sensitivity, while value exhibits the highest specificity. The D and combined model had the highest AUC and accuracy. D and ADC values showed high correlation between sequences, and moderate. Bland-Altman plot demonstrated unbiased parameter values. CONCLUSION: SMS-SSEPI-DWI FROC model provides good image quality and lesion characteristic values within an acceptable time. It shows consistent diagnostic performance compared to SSEPI-DWI, particularly in D and values, and significantly reduces scanning time.

Centipeda minima and 6-O-angeloylplenolin enhance the efficacy of immune checkpoint inhibitors in non-small cell lung cancer.

BACKGROUND: Chemotherapeutic agents including cisplatin, gemcitabine, and pemetrexed, significantly enhance the efficacy of immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC) by increasing PD-L1 expression and potentiating T cell cytotoxicity. However, the low response rate and adverse effects limit the application of chemotherapy/ICI combinations in patients. METHODS: We screened for medicinal herbs that could perturb PD-L1 expression and enhance T cell cytotoxicity in the presence of anti-PD-L1 antibody, and investigated the underlying mechanisms. RESULTS: We found that the aqueous extracts of Centipeda minima (CM) significantly enhanced the cancer cell-killing activity and granzyme B expression level of CD8+ T cells, in the presence of anti-PD-L1 antibody. Both CM and its active component 6-O-angeloylplenolin (6-OAP) upregulated PD-L1 expression by suppressing GSK-3ß-ß-TRCP-mediated ubiquitination and degradation. CM and 6-OAP significantly enhanced ICI-induced reduction of tumor burden and prolongation of overall survival of mice bearing NSCLC cells, accompanied by upregulation of PD-L1 and increase of CD8+ T cell infiltration. CM also exhibited anti-NSCLC activity in cells and in a patient-derived xenograft mouse model. CONCLUSIONS: These data demonstrated that the induced expression of PD-L1 and enhancement of CD8+ T cell cytotoxicity underlay the beneficial effects of 6-OAP-rich CM in NSCLCs, providing a clinically available and safe medicinal herb for combined use with ICIs to treat this deadly disease.

A novel OsGST gene encoding 9glutathione reductase negatively regulates cadmium accumulation in rice.

Cadmium (Cd) accumulates in rice and then moves up the food chain, causing serious health problems for humans. Glutathione S-transferase (GST) binds exogenous hazardous compounds to glutathione (GSH), which performs a variety of roles in plant responses to Cd stress. Here, Cd stimulated the transcripts of a novel OsGST gene, and the OsGST protein, which was localized in the nucleus and cytoplasm, was also induced by Cd. In OsGST deletion mutant lines generated by CRISPR/Cas9, more Cd was accumulated, and Cd hypersensitive phenotypes were observed, while transgenic lines overexpressing OsGST exhibited enhanced Cd tolerance and less Cd accumulation. Further analysis indicated that the osgst mutants exhibited considerably greater reactive oxygen species (ROS) and higher GSH level, and the antioxidant activity associated genes' expression were down-regulated, imply that OsGST controlled rice Cd accumulation and resistance through preserving the equilibrium of the GSH and redox in rice.

Incidence and Outcomes of Cardiocerebral Infarction: A Cohort Study of 2 National Population-Based Registries.

BACKGROUND: Cardiocerebral infarction (CCI), which is concomitant with acute myocardial infarction (AMI) and acute ischemic stroke (AIS), is a rare but severe presentation. However, there are few data on CCI, and the treatment options are uncertain. We investigated the characteristics and outcomes of CCI compared with AMI or AIS alone. METHODS: We performed a retrospective cohort study of 120 531 patients with AMI and AIS from the national stroke and AMI registries in Singapore. Patients were categorized into AMI only, AIS only, synchronous CCI (same-day), and metachronous CCI (within 1 week). The primary outcome was all-cause mortality, and the secondary outcome was cardiovascular mortality. The mortality risks were compared using Cox regression. Multivariable models were adjusted for baseline demographics, clinical variables, and treatment for AMI or AIS. RESULTS: Of 127 919 patients identified, 120 531 (94.2%) were included; 74 219 (61.6%) patients had AMI only, 44 721 (37.1%) had AIS only, 625 (0.5%) had synchronous CCI, and 966 (0.8%) had metachronous CCI. The mean age was 67.7 (SD, 14.0) years. Synchronous and metachronous CCI had a higher risk of 30-day mortality (synchronous: adjusted HR [aHR], 2.41 [95% CI, 1.77-3.28]; metachronous: aHR, 2.80 [95% CI, 2.11-3.73]) than AMI only and AIS only (synchronous: aHR, 2.90 [95% CI, 1.87-4.51]; metachronous: aHR, 4.36 [95% CI, 3.03-6.27]). The risk of cardiovascular mortality was higher in synchronous and metachronous CCI than AMI (synchronous: aHR, 3.03 [95% CI, 2.15-4.28]; metachronous: aHR, 3.41 [95% CI, 2.50-4.65]) or AIS only (synchronous: aHR, 2.58 [95% CI, 1.52-4.36]; metachronous: aHR, 4.52 [95% CI, 2.95-6.92]). In synchronous CCI, AMI was less likely to be managed with PCI and secondary prevention medications (P<0.001) compared with AMI only. CONCLUSIONS: Synchronous CCI occurred in 1 in 200 cases of AIS and AMI. Synchronous and metachronous CCI had higher mortality than AMI or AIS alone.

A detailed analysis of 16S rRNA gene sequencing and conventional PCR-based testing for the diagnosis of bacterial pathogens and discovery of novel bacteria.

This study represents the first analysis of the bacterial community in chickens affected by swollen head syndrome, utilizing 16S rRNA gene sequencing. Samples were obtained from clinical laying chickens and were examined for the presence of Avibacterium paragallinarum (APG) and Ornithobacterium rhinotracheale (ORT) using conventional polymerase chain reaction (PCR). From the samples, five APG-positive (APG) and APG-negative (N-APG) samples were chosen, along with five specific pathogen-free chickens, for 16S rRNA gene sequencing. Results showed that APG and ORT were widely detected in the chicken samples with swollen head syndrome (SHS, 9/10), while APG was detected in all five specific pathogen-free (SPF) samples. In contrast, conventional PCR sensitivity was found to be inadequate for diagnosis, with only 35.7% (5/14) and 11.1% (1/9) sensitivity for APG and ORT, respectively, based on 16S rRNA gene sequencing data. Furthermore, 16S rRNA gene sequencing was able to quantify the bacteria in the samples, revealing that the relative abundance of APG in the APG group ranged from 2.7 to 81.3%, while the relative abundance of APG in the N-APG group ranged from 0.1 to 21.0%. Notably, a low level of APG was also detected in all 5 SPF samples. The study also identified a significant number of animal and human common bacterial pathogens, including but not limited to Gallibacterium anatis, Riemerella columbina, Enterococcus cecorum, Mycoplasma synoviae, Helicobacter hepaticus, and Staphylococcus lentus. In conclusion, 16S rRNA gene sequencing is a valuable tool for bacterial pathogen diagnosis and the discovery of novel bacterial pathogens, while conventional PCR is not reliable for diagnosis.

[Quality control method for phenolic acid components in abandoned stems and leaves of Artemisia selengensis based on UPLC fingerprint combined with quantitative analysis of multi-components by single marker (QAMS)].

This study established an ultra-performance liquid chromatography(UPLC) fingerprint of abandoned stems and leaves of Artemisia selengensis and quantitative analysis of multi-components by single marker(QAMS) for five phenolic acid components. Waters Acquity UPLC BEH C_(18) chromatography column(2.1 mm×100 mm, 1.7 µm) was used. The gradient elution was carried out with the mobile phase composed of 0.1% phosphoric acid water and acetonitrile at a flow rate of 0.3 mL·min~(-1) and a column temperature at 30 ℃. The detection wavelength was 330 nm, and the injection volume was 2 µL. Similarity evaluation and cluster analysis were conducted on the fingerprint data, and 15 common components in 13 batches of abandoned stems and leaves of A. selengensis were identified. The relative correction factors of ferulic acid, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C were calculated using chlorogenic acid as the internal reference. The QAMS for determining five components in the abandoned stems and leaves of A. selengensis was established. At the same time, the content of these five components was determined using the external standard method(ESM), and the results showed that there were no significant differences in their content determined by the QAMS and the ESM. The results indicated that the content of phenolic acid components in the abandoned stems and leaves of A. selengensis from different varieties and different origins had obvious differences. In addition, the content of phenolic acid components in the abandoned stems and leaves of lignified A. selengensis was significantly higher than that of non-lignified A. selengensis. In summary, QAMS established in this study can be quickly, accurately, and economically used to determine the content of five phenolic acid components in abandoned stems and leaves of A. selengensis, laying a foundation for the resource development and utilization of abandoned stems and leaves of A. selengensis.

Genome-wide association studies on resistance to powdery mildew in cultivated emmer wheat.

Powdery mildew, caused by the fungal pathogen Blumeria graminis (DC.) E. O. Speer f. sp. tritici Em. Marchal (Bgt), is a constant threat to global wheat (Triticum aestivum L.) production. Although ∼100 powdery mildew (Pm) resistance genes and alleles have been identified in wheat and its relatives, more is needed to minimize Bgt's fast evolving virulence. In tetraploid wheat (Triticum turgidum L.), wild emmer wheat [T. turgidum ssp. dicoccoides (Körn. ex Asch. & Graebn.) Thell.] accessions from Israel have contributed many Pm resistance genes. However, the diverse genetic reservoirs of cultivated emmer wheat [T. turgidum ssp. dicoccum (Schrank ex Schübl.) Thell.] have not been fully exploited. In the present study, we evaluated a diverse panel of 174 cultivated emmer accessions for their reaction to Bgt isolate OKS(14)-B-3-1 and found that 66% of accessions, particularly those of Ethiopian (30.5%) and Indian (6.3%) origins, exhibited high resistance. To determine the genetic basis of Bgt resistance in the panel, genome-wide association studies were performed using 46,383 single nucleotide polymorphisms (SNPs) from genotype-by-sequencing and 4331 SNPs from the 9K SNP Infinium array. Twenty-five significant SNP markers were identified to be associated with Bgt resistance, of which 21 SNPs are likely novel loci, whereas four possibly represent emmer derived Pm4a, Pm5a, PmG16, and Pm64. Most novel loci exhibited minor effects, whereas three novel loci on chromosome arms 2AS, 3BS, and 5AL had major effect on the phenotypic variance. This study demonstrates cultivated emmer as a rich source of powdery mildew resistance, and the resistant accessions and novel loci found herein can be utilized in wheat breeding programs to enhance Bgt resistance in wheat.