Mapping of a Wheat Resistance Gene to Yellow Mosaic Disease by Amplified Fragment Length Polymorphism and Simple Sequence Repeat Markers

Wheat （Triticum aestivum L.） yellow mosaic virus （WYMV） is transmitted by a fungal vector through soil and causes serious wheat yield losses due to yellow mosaic disease, with yellow-streaked leaves and stunted plants. In the present study, the amplified fragment length polymorphisms （AFLP） and simple sequence repeat （SSR） were used to identify the molecular linkages with the resistance gene against WYMV. Bulked segregant analysis was performed with an F2 population derived from the cross of cultivar Ningmai 9 （resistant） × cultivar Yangmai 10 （susceptible）. By screening among the resistant or susceptible parents, the F2 pools and the individuals in the F2 population with 64 combined selective AFLP primers （EcoRI/MseI） or 290 reported SSR primers, a polymorphic DNA segment （approximately 120 bp） was amplified using the primer pair E2/M5, and an SSR marker （approximately 180 bp） was located on wheat chromosome 2A using the primer Xgwm328. Analysis with MAPMAKER/Exp Version 3.0b （Whitehead institute for Biomedical Research, Cambridge, MA, USA） indicated that these two markers were dominantly associated with the resistance gene at distances of 5.4 cM or 17.6 cM, respectively. The resistance gene to WYMV derived from Ningmai 9, is temporarily named YmNM, and was mapped to wheat chromosome 2A.

Hepatic protective effects of Shenling Baizhu powder, a herbal compound, against inflammatory damage via TLR4/NLRP3 signalling pathway in rats with nonalcoholic fatty liver disease

Objective: High-fat diet(HFD) and inflammation are two key contributors to nonalcoholic fatty liver disease(NAFLD). Shenling Baizhu powder(SLBZP), a classical herbal compound, has been successfully used to alleviate NAFLD. However, its specific mechanisms are not fully understood. In this study, we assessed the anti-NAFLD effect of SLBZP in vivo.Methods: Rats were fed an HFD with or without SLBZP or with probiotics. At the end of week 16, an echo magnetic resonance imaging(EchoMRI) body composition analyser was used to quantitatively analyse body composition;a micro-computed tomography(micro-CT) imaging system was used to evaluate whole body and liver fat;and the Moor full-field laser perfusion imager 2 was used to assess liver microcirculation, after which, all rats were sacrificed. Then, biochemical indicators in the blood and the ultrastructure of rat livers were evaluated. Protein expression related to the liver Toll-like receptor 4(TLR4)/Nod-like receptor family pyrin domain-containing 3(NLRP3) signalling pathway was assessed using Western blot analysis. Further, high-throughput screening of 29 related inflammatory factors in liver tissue was performed using a cytokine array.Results: SLBZP supplementation reduced body weight, serum free fatty acid, and insulin resistance index(P<0.05). It also ameliorated liver microcirculation and ultrastructural abnormalities. EchoMRI and micro-CT quantitative analyses showed that treatment with SLBZP reduced fat mass and visceral fat(P<0.05 and P<0.01, respectively). In addition, SLBZP decreased the expression of lipopolysaccharide(LPS)-activated TLR4/NLRP3 signalling pathway-related proteins and altered the expression levels of some inflammatory cytokines in liver tissues.Conclusion: SLBZP can inhibit NLRP3 inflammasome activation and interleukin-1 b release by suppressing LPS-induced TLR4 expression in rats with HFD-induced NAFLD. Thus, SLBZP may be beneficial for the prevention and treatment of inflammatory damage and associated diseases.

Metagenomic analysis reveals oropharyngeal microbiota alterations in patients with COVID-19

COVID-19 remains a serious emerging global health problem,and little is known about the role of oropharynx commensal microbes in infection susceptibility and severity.Here,we present the oropharyngeal microbiota characteristics identified by shotgun metagenomic sequencing analyses of oropharynx swab specimens from 31 COVID-19 patients,29 influenza B patients,and 28 healthy controls.Our results revealed a distinct oropharyngeal microbiota composition in the COVID-19 patients,characterized by enrichment of opportunistic pathogens such as Veillonella and Megasphaera and depletion of Pseudopropionibacterium,Rothia,and Streptococcus.Based on the relative abundance of the oropharyngeal microbiome,we built a microbial classifier to distinguish COVID-19 patients from flu patients and healthy controls with an AUC of 0.889,in which Veillonella was identified as the most prominent biomarker for COVID-19 group.Several members of the genus Veillonella,especially Veillonella parvula which was highly enriched in the oropharynx of our COVID-19 patients,were also overrepresented in the BALF of COVID-19 patients,indicating that the oral cavity acts as a natural reservoir for pathogens to induce co-infections in the lungs of COVID-19 patients.We also found the increased ratios of Klebsiella sp.,Acinetobacter sp.,and Serratia sp.were correlated with both disease severity and elevated systemic inflammation markers(neutrophil-lymphocyte ratio,NLR),suggesting that these oropharynx microbiota alterations may impact COVID-19 severity by influencing the inflammatory response.Moreover,the oropharyngeal microbiome of COVID-19 patients exhibited a significant enrichment in amino acid metabolism and xenobiotic biodegradation and metabolism.In addition,all 26 drug classes of antimicrobial resistance genes were detected in the COVID-19 group,and were significantly enriched in critical cases.In conclusion,we found that oropharyngeal microbiota alterations and functional differences were associated with COVID-19 severity.