Construction of Genetic Map and QTL Mapping for Seed Size and Quality Traits in Soybean (Glycine max L.).

Soybean (Glycine max L.) is the main source of vegetable protein and edible oil for humans, with an average content of about 40% crude protein and 20% crude fat. Soybean yield and quality traits are mostly quantitative traits controlled by multiple genes. The quantitative trait loci (QTL) mapping for yield and quality traits, as well as for the identification of mining-related candidate genes, is of great significance for the molecular breeding and understanding the genetic mechanism. In this study, 186 individual plants of the F2 generation derived from crosses between Changjiangchun 2 and Yushuxian 2 were selected as the mapping population to construct a molecular genetic linkage map. A genetic map containing 445 SSR markers with an average distance of 5.3 cM and a total length of 2375.6 cM was obtained. Based on constructed genetic map, 11 traits including hundred-seed weight (HSW), seed length (SL), seed width (SW), seed length-to-width ratio (SLW), oil content (OIL), protein content (PRO), oleic acid (OA), linoleic acid (LA), linolenic acid (LNA), palmitic acid (PA), stearic acid (SA) of yield and quality were detected by the multiple- d size traits and 113 QTLs related to quality were detected by the multiple QTL model (MQM) mapping method across generations F2, F2:3, F2:4, and F2:5. A total of 71 QTLs related to seed size traits and 113 QTLs related to quality traits were obtained in four generations. With those QTLs, 19 clusters for seed size traits and 20 QTL clusters for quality traits were summarized. Two promising clusters, one related to seed size traits and the other to quality traits, have been identified. The cluster associated with seed size traits spans from position 27876712 to 29009783 on Chromosome 16, while the cluster linked to quality traits spans from position 12575403 to 13875138 on Chromosome 6. Within these intervals, a reference genome of William82 was used for gene searching. A total of 36 candidate genes that may be involved in the regulation of soybean seed size and quality were screened by gene functional annotation and GO enrichment analysis. The results will lay the theoretical and technical foundation for molecularly assisted breeding in soybean.

Vaccines reduced hospital length of stay and fraction of inspired oxygen of COVID-19 patients: A retrospective cohort study.

Few studies have focused on the evaluation of vaccine effectiveness (VE) in mainland China. This study was to characterize the VE including the frequent symptoms, laboratory indices, along with endotracheal intubation, hospital length of stay (LoS), and survival status. This retrospective cohort study included patients with COVID-19 admitted to our hospital. Statistical comparisons of continuous variables were carried out with an independent Student's t-test or Mann-Whitney U test. For categorical variables, the Chi-square test and Fisher exact test were used. Multivariable regression analysis was performed to adjust the confounding factors such as age, gender, body mass index (BMI), residential area, smoking status, the Charlson comorbidity index (CCI) score, followed by investigating the effects of vaccination on critical ill prevention, reduced mortality and endotracheal intubation, LoS and inspired oxygen. This study included 549 hospitalized patients with COVID-19, including 222 (40.43 %) vaccinated participants and 327 (59.57 %) unvaccinated counterparts. There was no obvious difference between the two groups in typical clinical symptoms of COVID-19, clinical laboratory results and mortality. Multivariable analysis showed that COVID-19 vaccine obviously reduced LoS by 1.2 days (lnLoS = -0.14, 95 %CI[-0.24,-0.04]; P = 0.005) and decreased fraction of inspired oxygen by 40 % (OR: 0.60; 95 %CI[0.40,0.90]; P = 0.013) after adjusting age, gender, BMI, residential area, smoking status and CCI score. In contrast, vaccination induced reduction in the critically ill, mortality, and endotracheal intubation compared with the unvaccinated counterparts, but with no statistical differences. Vaccinated patients hospitalized with COVID-19 have a reduced LoS and fraction of inspired oxygen compared to unvaccinated cases in China.

Subplenones A-J: Dimeric Xanthones with Antibacterial Activity from the Endophytic Fungus Subplenodomus sp. CPCC 401465.

Subplenones A-J (1-10), 10 new xanthone dimers, have been isolated and characterized from the endophytic fungus Subplenodomus sp. CPCC 401465, which resides within the Chinese medicinal plant Gentiana straminea. The isolation process was guided by antibacterial assays and molecular-networking-based analyses. The chemical structures of these compounds were elucidated through the interpretation of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HRESIMS) data. Furthermore, the relative configuration of the compounds was determined using NMR and single-crystal X-ray diffraction analyses, and the absolute configuration was established using electronic circular dichroism calculations. All of the isolated compounds exhibited significant inhibitory activity against Gram-positive bacteria. Notably, compounds 1, 5, and 7 displayed remarkable inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 700698, with a minimum inhibitory concentration (MIC) of 0.25 µg/mL, and against vancomycin-resistant Enterococcus faecium (VRE) ATCC 700221, with MIC values ranging from 0.5 to 1.0 µg/mL.

Transcriptomic and Metabolomic Analyses Reveal the Key Genes Related to Shade Tolerance in Soybean.

Soybean (Glycine max) is an important crop, rich in proteins, vegetable oils and several other phytochemicals, which is often affected by light during growth. However, the specific regulatory mechanisms of leaf development under shade conditions have yet to be understood. In this study, the transcriptome and metabolome sequencing of leaves from the shade-tolerant soybean 'Nanxiadou 25' under natural light (ND1) and 50% shade rate (SHND1) were carried out, respectively. A total of 265 differentially expressed genes (DEGs) were identified, including 144 down-regulated and 121 up-regulated genes. Meanwhile, KEGG enrichment analysis of DEGs was performed and 22 DEGs were significantly enriched in the top five pathways, including histidine metabolism, riboflavin metabolism, vitamin B6 metabolism, glycerolipid metabolism and cutin, suberine and wax biosynthesis. Among all the enrichment pathways, the most DEGs were enriched in plant hormone signaling pathways with 19 DEGs being enriched. Transcription factors were screened out and 34 differentially expressed TFs (DETFs) were identified. Weighted gene co-expression network analysis (WGCNA) was performed and identified 10 core hub genes. Combined analysis of transcriptome and metabolome screened out 36 DEGs, and 12 potential candidate genes were screened out and validated by quantitative real-time polymerase chain reaction (qRT-PCR) assay, which may be related to the mechanism of shade tolerance in soybean, such as ATP phosphoribosyl transferase (ATP-PRT2), phosphocholine phosphatase (PEPC), AUXIN-RESPONSIVE PROTEIN (IAA17), PURPLE ACID PHOSPHATASE (PAP), etc. Our results provide new knowledge for the identification and function of candidate genes regulating soybean shade tolerance and provide valuable resources for the genetic dissection of soybean shade tolerance molecular breeding.

Joint QTL Mapping and Transcriptome Sequencing Analysis Reveal Candidate Seed-Shattering-Related Genes in Common Buckwheat.

Common buckwheat (Fagopyrum esculentum M.) is an important traditional miscellaneous grain crop. However, seed-shattering is a significant problem in common buckwheat. To investigate the genetic architecture and genetic regulation of seed-shattering in common buckwheat, we constructed a genetic linkage map using the F2 population of Gr (green-flower mutant and shattering resistance) and UD (white flower and susceptible to shattering), which included eight linkage groups with 174 loci, and detected seven QTLs of pedicel strength. RNA-seq analysis of pedicel in two parents revealed 214 differentially expressed genes DEGs that play roles in phenylpropanoid biosynthesis, vitamin B6 metabolism, and flavonoid biosynthesis. Weighted gene co-expression network analysis (WGCNA) was performed and screened out 19 core hub genes. Untargeted GC-MS analysis detected 138 different metabolites and conjoint analysis screened out 11 DEGs, which were significantly associated with differential metabolites. Furthermore, we identified 43 genes in the QTLs, of which six genes had high expression levels in the pedicel of common buckwheat. Finally, 21 candidate genes were screened out based on the above analysis and gene function. Our results provided additional knowledge for the identification and functions of causal candidate genes responsible for the variation in seed-shattering and would be an invaluable resource for the genetic dissection of common buckwheat resistance-shattering molecular breeding.

Natural variation of GhSI7 increases seed index in cotton.

KEY MESSAGE: qSI07.1, a major QTL for seed index in cotton, was fine-mapped to a 17.45-kb region, and the candidate gene GhSI7 was verified in transgenic plants. Improving production to meet human needs is a vital objective in cotton breeding. The yield-related trait seed index is a complex quantitative trait, but few candidate genes for seed index have been characterized. Here, a major QTL for seed index qSI07.1 was fine-mapped to a 17.45-kb region by linkage analysis and substitutional mapping. Only GhSI7, encoding the transcriptional regulator STERILE APETALA, was contained in the candidate region. Association test and genetic analysis indicated that an 845-bp-deletion in its intron was responsible for the seed index variation. Origin analysis revealed that this variation was unique in Gossypium hirsutum and originated from race accessions. Overexpression of GhSI7 (haplotype 2) significantly increased the seed index and organ size in cotton plants. Our findings provided a diagnostic marker for breeding and selecting cotton varieties with high seed index, and laid a foundation for further studies to understand the molecular mechanism of cotton seed morphogenesis.

An anti-influenza A virus microbial metabolite acts by degrading viral endonuclease PA.

The emergence of new highly pathogenic and drug-resistant influenza strains urges the development of novel therapeutics for influenza A virus (IAV). Here, we report the discovery of an anti-IAV microbial metabolite called APL-16-5 that was originally isolated from the plant endophytic fungus Aspergillus sp. CPCC 400735. APL-16-5 binds to both the E3 ligase TRIM25 and IAV polymerase subunit PA, leading to TRIM25 ubiquitination of PA and subsequent degradation of PA in the proteasome. This mode of action conforms to that of a proteolysis targeting chimera which employs the cellular ubiquitin-proteasome machinery to chemically induce the degradation of target proteins. Importantly, APL-16-5 potently inhibits IAV and protects mice from lethal IAV infection. Therefore, we have identified a natural microbial metabolite with potent in vivo anti-IAV activity and the potential of becoming a new IAV therapeutic. The antiviral mechanism of APL-16-5 opens the possibility of improving its anti-IAV potency and specificity by adjusting its affinity for TRIM25 and viral PA protein through medicinal chemistry.

Inflorescence Transcriptome Sequencing and Development of New EST-SSR Markers in Common Buckwheat (Fagopyrum esculentum).

Common buckwheat (Fagopyrum esculentum M.) is known for its adaptability, good nutrition, and medicinal and health care value. However, genetic studies of buckwheat have been hindered by limited genomic resources and genetic markers. In this study, Illumina HiSeq 4000 high-throughput sequencing technology was used to sequence the transcriptome of green-flower common buckwheat (Gr) with coarse pedicels and white-flower Ukrainian daliqiao (UD) with fine pedicels. A total of 118,448 unigenes were obtained, with an average length of 1248 bp and an N50 of 1850 bp. A total of 39,432 differentially expressed genes (DEGs) were identified, and the DEGs of the porphyrins and chlorophyll metabolic pathway had significantly upregulated expression in Gr. Then, a total of 17,579 sequences containing SSR loci were detected, and 20,756 EST-SSR loci were found. The distribution frequency of EST-SSR in the transcriptome was 17.52%, and the average distribution density was 8.21 kb. A total of 224 pairs of primers were randomly selected for synthesis; 35 varieties of common buckwheat and 13 varieties of Tartary buckwheat were verified through these primers. The clustering results well verified the previous conclusion that common buckwheat and Tartary buckwheat had a distant genetic relationship. The EST-SSR markers identified and developed in this study will be helpful to enrich the transcriptome information and marker-assisted selection breeding of buckwheat.

Transcriptome and metabolome analyses reveal the key genes related to grain size of big grain mutant in Tartary Buckwheat (Fagopyrum tartaricum).

Grain size with high heritability and stability is an important selection target during Tartary buckwheat breeding. However, the mechanisms that regulate Tartary buckwheat grain development are unknown. We generated transcriptome and metabolome sequencing from 10 and 15 days past anthesis (DPA) grains of big grain mutant (bg1) and WT, and identified 4108 differentially expressed genes (DEGs) including 93 significantly up-regulated differential genes and 85 significantly down-regulated genes in both stages, simultaneously. Meanwhile, we identified DEGs involved in ubiquitin-proteasome pathway, HAI-KU (IKU) pathway, mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone (auxin, brassinosteroids and cytokinins) transduction pathway and five transcription factor families, including APETALA (AP2), GROWTH-REGULATING FACTORS (GRF), AUXIN RESPONSE FACTOR (ARF), WRKY and MYB. Weighted gene co-expression network analysis (WGCNA) was performed and obtained 9 core DEGs. Conjoint analyses of transcriptome and metabolome sequencing screened out 394 DEGs. Using a combined comprehensive analysis, we identified 24 potential candidate genes that encode E3 ubiquitin-protein ligase HIP1, EMBRYO-DEFECTIVE (EMB) protein, receptor-like protein kinase FERONIA (FER), kinesin-4 protein SRG1, and so on, which may be associated with the big-grain mutant bg1. Finally, a quantitative real-time Polymerase Chain Reaction (qRT-PCR) assay was conducted to validate the identified DEGs. Our results provide additional knowledge for identification and functions of causal candidate genes responsible for the variation in grain size and will be an invaluable resource for the genetic dissection of Tartary buckwheat high-yield molecular breeding.

Isolation, Characterization, and Antimicrobial Activity of Bacterial and Fungal Representatives Associated With Particulate Matter During Haze and Non-haze Days.

Particulate matter (PM) has been a threat to the environment and public health in the metropolises of developing industrial countries such as Beijing. The microorganisms associated with PM have an impact on human health if they are exposed to the respiratory tract persistently. There are few reports on the microbial resources collected from PM and their antimicrobial activities. In this study, we greatly expanded the diversity of available commensal organisms by collecting 1,258 bacterial and 456 fungal isolates from 63 PM samples. A total of 77 bacterial genera and 35 fungal genera were included in our pure cultures, with Bacillus as the most prevalent cultured bacterial genus, Aspergillus, and Penicillium as the most prevalent fungal ones. During heavy-haze days, the numbers of colony-forming units (CFUs) and isolates of bacteria and fungi were decreased. Bacillus, Paenibacillus, and Chaetomium were found to be enriched during haze days, while Kocuria, Microbacterium, and Penicillium were found to be enriched during non-haze days. Antimicrobial activity against common pathogens have been found in 40 bacterial representatives and 1 fungal representative. The collection of airborne strains will provide a basis to greatly increase our understanding of the relationship between bacteria and fungi associated with PM and human health.

Dioscin facilitates ROS-induced apoptosis via the p38-MAPK/HSP27-mediated pathways in lung squamous cell carcinoma.

Lung squamous cell carcinoma (SCC) is one of the deadliest cancers both in China and worldwide. To date, the efficacy of lung SCC treatments is limited. Recent studies have elucidated the powerful anti-tumour role of dioscin in different human cancers. Here, our study aims to investigate the effect of dioscin on lung SCC and its underlying mechanism. First, we found that dioscin not only inhibited cell proliferation and cell migration and induced cell apoptosis in lung SCC cells but also suppressed tumour growth in tumour-bearing mice. Furthermore, we noted that the accumulation of intracellular reactive oxygen species (ROS) was triggered by dioscin in lung SCC cells, leading to the phosphorylation of HSP27 through p38-MAPK and consequent cell apoptosis. The activation of p38-MAPK/HSP27 induced by the p38-MAPK activator Anisomycin enhanced the apoptosis of lung SCC cells, while the ROS inhibitor N-acetyl-L-cysteine (NAC) and the p38-MAPK inhibitor SB203580 both attenuated dioscin-mediated cell apoptosis. Moreover, NAC suppressed the activation of p38-MAPK/HSP27 that induced by dioscin. In conclusion, these results confirm that dioscin facilitates ROS-induced apoptosis via the p38-MAPK/HSP27-mediated pathway in lung SCC.

Ornithinimicrobium cerasi sp. nov., isolated from the fruit of Cerasus pseudocerasus and emended description of the genus Ornithinimicrobium.

Strain CPCC 203383T, isolated from the surface-sterilized fruit of Cerasus pseudocerasus (Lindl.) G. Don, was taxonomically characterized based on a polyphasic investigation. It had the highest 16S rRNA gene sequence similarities with Ornithinimicrobium pekingense DSM 21552 (97.2 %) and O. kibberense DSM 17687T (97.2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain formed a distinct phyletic branch within the genus Ornithinimicrobium and the whole genome sequence data analyses supported that strain CPCC 203383T was phylogenetically related to the Ornithinimicrobium species. The isolate shared a range of phenotypic patterns reported for members of the genus Ornithinimicrobium, but also had a range of cultural, physiological and biochemical characteristics that separated it from related Ornithinimicrobium species. The menaquinone was MK-8(H4). The polar lipid profile consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylinositol (PI) and unidentified lipids (ULs). The major fatty acids (>5 %) were iso-C15 : 0, anteiso-C15 : 0, iso-C16:0, 9-methyl C16 : 0, iso-C17 : 0 and anteiso-C17 : 0. The cell wall peptidoglycan contains l-ornithine as diagnostic diamino acid and an interpeptide bridge consisting of L-Orn←L-Ala←Gly←D-Asp. The combined genotypic and phenotypic data indicated that the isolate represents a novel species of the genus Ornithinimicrobium, for which the name Ornithinimicrobium cerasi sp. nov. is proposed, with CPCC 203383T(=NBRC 113522T=KCTC 49200T) as the type strain. The DNA G+C composition is 72.3 mol%. The availability of new data allows for an emended description of the genus Ornithinimicrobium.

De novo transcriptome assembly and identification of genes related to seed size in common buckwheat (Fagopyrum esculentum M.).

Common buckwheat (Fagopyrum esculentum M.) belongs to the eudicot family Polygonaceae, Fagopyrum Mill, and its seeds have high nutritional value. The mechanism of seed development of common buckwheat remains unclear at the molecular level and no genes related to seed size have been identified. In this study, we performed genome-wide transcriptome sequencing and analysis using common buckwheat seeds at 5 days post anthesis (DPA) and 10 DPA from two cultivars (large-seeded and small-seeded). A total of 259,895 transcripts were assembled, resulting in 187,034 unigenes with average length of 1097 bp and N50 of 1538 bp. Based on gene expression profiles, 9127 differentially expressed genes (DEGs) were identified and analyzed in GO enrichment and KEGG analysis. In addition, genes related to seed size in the IKU pathway, ubiquitin-proteasome pathway, MAPK signaling pathway, TFs and phytohormones were identified and analyzed. AP2 and bZIP transcription factors, BR-signal and ABA were considered to be important regulators of seed size. This study provides a valuable genetic resource for future identification and functional analysis of candidate genes regulating seed size in common buckwheat and will be useful for improving seed yield in common buckwheat through molecular breeding in the future.

Bacterial community pattern along the sediment seafloor of the Arctic fjorden (Kongsfjorden, Svalbard).

The Arctic region has been the focus of increasing attention as an ecosystem that is highly sensitive to changes associated with global warming. Although it was assumed to be vulnerable to changes in climate, a limited number of studies have been conducted on the surface sediment bacteria of Arctic fjorden. This study assessed the diversity and distribution pattern of bacterial communities in eight marine sediments along the seafloor in a high Arctic fjorden (Kongsfjorden, Svalbard). A total of 822 operational taxonomic units (OTUs) were identified by Illumina MiSeq sequencing, targeting the V3-V4 hypervariable regions of the 16S rRNA gene. In these surface marine sediments, more than half of the sequences belonged to the phylum Proteobacteria, followed by Bacteroidetes, Verrucomicrobia, Actinobacteria, Chloroflexi and Lentisphaerae. The bacterial genera Marinicella, Desulfobulbus, Lutimonas, Sulfurovum and clade SEEP-SRB4 were dominant in all samples. Analysis of similarity indicated that bacterial communities were significantly different among the inner, central and outer basins (r2 = 0.5, P = 0.03 < 0.05). Canonical correspondence analysis and permutation tests revealed that location depth (r2 = 0.87, P < 0.01), temperature (r2 = 0.88, P < 0.01) and salinity (r2 = 0.88, P < 0.05) were the most significant factors that correlated with the bacterial communities in the sediments. 28 differentially abundant taxonomic clades in the inner and outer basin with an LDA score higher than 2.0 were found by the LEfSe method. The Spearman correlation heat map revealed different degrees of correlation between most major OTUs and environmental factors, while some clades have an inverse correlation with environmental factors. The spatial patterns of bacterial communities along the Kongsfjorden may offer insight into the ecological responses of prokaryotes to climate change in the Arctic ecosystem, which makes it necessary to continue with monitoring.

Roseomonas globiformis sp. nov., an airborne bacteria isolated from an urban area of Beijing.

A novel dark pink pigmented bacterium, designated strain CPCC 100847T (deposited with strain code 0113-15), was isolated from the urban air of Beijing, China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CPCC 100847T was related to members of the genus Roseomonas and had the highest 16S rRNA gene sequence similarity to Roseomonas aestuarii JC17T (97.5 %). A low level of DNA-DNA relatedness (18.7 %) with its closest type strain R. aestuarii JC17T (KCTC 22692T) proved that strain CPCC 100847T belonged to a unique genomic species. CPCC 100847T had many common characteristics of the genus Roseomonas, but also had a range of cultural, physiological and biochemical characteristics that separated it from related Roseomonas species. Cells were Gram-negative, cocci- to oval-shaped, non-motile, non-endospore-forming and strictly aerobic. The respiratory ubiquinone was Q-10. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid and an unidentified phospholipid. The major fatty acids (>5 %) were C18 : 1ω7c, anteiso-C15 : 0, C16 : 0, iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The combined genotypic and phenotypic data indicated that the isolate represents a novel species of the genus Roseomonas. The name proposed for this species is Roseomonasglobiformis sp. nov., with CPCC 100847T (=KCTC 52094T) as the type strain. The DNA G+C composition is 65.2 mol%.

Glycomyces paridis sp. nov., isolated from the medicinal plant Paris polyphylla.

Three actinomycete strains originating from the surface-sterilized roots of Paris polyphylla were characterized by using a polyphasic approach. Phylogenetic analyses based on the 16S rRNA gene sequence showed that they formed a deep, monophyletic branch in the genus Glycomyces, and were most closely related to the type strains of the species Glycomyces harbinensis and Glycomycesscopariae. Morphological and chemotaxonomic data supported the affiliation of strains CPCC 204357T, CPCC 204354 and CPCC 204355 to the genus Glycomyces. The results of physiological and biochemical tests allowed phenotypic differentiation of strains CPCC 204357T, CPCC 204354 and CPCC 204355 from their closest phylogenetic related species in the genus Glycomyces. Low levels of DNA-DNA relatedness with its closest type strains of G. harbinensis and G. scopariaeindicated that strain CPCC 204357T represent a novel species, for which the name Glycomyces paridis sp. nov. is proposed, with CPCC 204357T (=DSM 102295T=KCTC 39745T) as the type strain.

Structural Variation in the Bacterial Community Associated with Airborne Particulate Matter in Beijing, China, during Hazy and Nonhazy Days.

The structural variation of the bacterial community associated with particulate matter (PM) was assessed in an urban area of Beijing during hazy and nonhazy days. Sampling for different PM fractions (PM2.5 [<2.5 µm], PM10 [<10 µm], and total suspended particulate) was conducted using three portable air samplers from September 2014 to February 2015. The airborne bacterial community in these samples was analyzed using the Illumina MiSeq platform with bacterium-specific primers targeting the 16S rRNA gene. A total of 1,707,072 reads belonging to 6,009 operational taxonomic units were observed. The airborne bacterial community composition was significantly affected by PM fractions (R = 0.157, P < 0.01). In addition, the relative abundances of several genera significantly differed between samples with various haze levels; for example, Methylobacillus, Tumebacillus, and Desulfurispora spp. increased in heavy-haze days. Canonical correspondence analysis and permutation tests showed that temperature, SO2 concentration, relative humidity, PM10 concentration, and CO concentration were significant factors that associated with airborne bacterial community composition. Only six genera increased across PM10 samples (Dokdonella, Caenimonas, Geminicoccus, and Sphingopyxis) and PM2.5 samples (Cellulomonas and Rhizobacter), while a large number of taxa significantly increased in total suspended particulate samples, such as Paracoccus, Kocuria, and Sphingomonas Network analysis indicated that Paracoccus, Rubellimicrobium, Kocuria, and Arthrobacter were the key genera in the airborne PM samples. Overall, the findings presented here suggest that diverse airborne bacterial communities are associated with PM and provide further understanding of bacterial community structure in the atmosphere during hazy and nonhazy days.IMPORTANCE The results presented here represent an analysis of the airborne bacterial community associated with particulate matter (PM) and advance our understanding of the structural variation of these communities. We observed a shift in bacterial community composition with PM fractions but no significant difference with haze levels. This may be because the bacterial differences are obscured by high bacterial diversity in the atmosphere. However, we also observed that a few genera (such as Methylobacillus, Tumebacillus, and Desulfurispora) increased significantly on heavy-haze days. In addition, Paracoccus, Rubellimicrobium, Kocuria, and Arthrobacter were the key genera in the airborne PM samples. Accurate and real-time techniques, such as metagenomics and metatranscriptomics, should be developed for a future survey of the relationship of airborne bacteria and haze.

C21 steroid derivatives from the Dai herbal medicine Dai-Bai-Jie, the dried roots of Marsdenia tenacissima, and their screening for anti-HIV activity.

Twenty-three new C21 steroidal glycosides, marstenacissides C1-C10 (1-10), D1-D7 (11-17) and E1-E6 (18-23), and four new C21 steroids, 11α,12ß-O-ditigloyl-tenacigenin C (24), 11α-O-benzoyl-12ß-O-tigloyl-tenacigenin C (25), 11α-O-tigloyl-12ß-O-benzoyl-tenacigenin C (26) and 11α-O-tigloyl-12ß-O-benzoyl-marsdenin (27), were isolated from the Dai herbal medicine Dai-Bai-Jie, derived from the roots of Marsdenia tenacissima. The chemical structures of all compounds were established by spectroscopic techniques, including high-resolution mass spectrometry and NMR spectroscopy, as well as by comparison with reported spectral data. The anti-HIV activities of these compounds were screened, and the compounds obtained displayed inhibitory effects against HIV-1 with inhibition rates of 36.4-81.3% at 30 µM.

Metabolites from the Plant Endophytic Fungus Aspergillus sp. CPCC 400735 and Their Anti-HIV Activities.

Thirty-three metabolites including five phenalenone derivatives (1-5), seven cytochalasins (6-12), thirteen butenolides (13-25), and eight phenyl derivatives (26-33) were isolated from Aspergillus sp. CPCC 400735 cultured on rice. The structures of all compounds were elucidated by NMR, MS, and CD experiments, of which 1-5 (asperphenalenones A-E), 6 (aspochalasin R), and 13 (aspulvinone R) were identified as new compounds. Specifically, asperphenalenones A-E (1-5) represent an unusual structure composed of a linear diterpene derivative linked to a phenalenone derivative via a C-C bond. Compounds 1, 4, 10, and 26 exhibited anti-HIV activity with IC50 values of 4.5, 2.4, 9.2, and 6.6 µM, respectively (lamivudine 0.1 µM; efavirenz, 0.4 × 10-3 µM).