[Spherical amino-functionalized covalent organic frameworks: Synthesis and adsorption performance toward perfluorinated compounds].

Perfluorinated compounds (PFCs) are widely used in textiles, fire protection, metal electroplating, and semiconductor production owing to their hydrophobic and oil-repellent characteristics. However, they are also persistent organic pollutants. The uncontrolled discharge of PFCs into the environment has led to serious global pollution. PFCs pose severe reproductive, neural, immune, and other threats to human health by accumulating through the food chain. Thus, the development and application of high-performance extraction materials has become a research hotspot in efforts to achieve the accurate detection of trace PFCs in environmental waters. Most traditional PFC adsorbents present a number of disadvantages, such as low adsorption selectivity, slow diffusion, and poor reusability. Covalent organic frameworks (COFs) are crystalline polymers with ordered porous structures, large specific surface areas, and high chemical and thermal stability. These frameworks can easily be functionalized for the desired purpose. In this paper, spherical amino-functionalized COFs (denoted COF-NH2) were fabricated via a two-step method to effectively enrich/remove PFCs from water. First, vinyl covalent organic framework (Vinyl COF) was synthesized at room temperature using 1,4-diradical-2,5-divinylbenzene (Dva) and 1,3,5-tris(4-aminophenyl)benzene (Tab) as building blocks. Then, thioether-bridged aromatic amine-functionalized spherical COF-NH2 was synthesized through a thiol-alkenyl click reaction using 4-aminothiophenol as the functional monomer. COF-NH2 showed good dispersion in water owing to its abundant amino groups, forming multiple hydrogen bonds with the F atoms of PFCs. The synergistic hydrophobic interactions between the organic skeleton of the COF and alkyl carbon chains of the PFCs led to enhanced adsorption efficiency. The produced Vinyl COF and COF-NH2 were characterized by Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and Brunner-Emmet-Teller (BET) measurements. The results confirmed that spherical COF-NH2 materials with a homogeneous size distribution were successfully fabricated. The obtained COF-NH2 microspheres had a diameter of approximately 500 nm and exhibited high thermal stability as well as a large specific surface area and pore volume. The adsorption kinetics, isotherm adsorption models, pH effects, and regeneration properties of COF-NH2 were also investigated, and the results indicated that the adsorption of PFCs by COF-NH2 conformed to the pseudo-second-order kinetic and Langmuir isotherm adsorption models. The obtained COF-NH2 microspheres can be applied over a wide pH range, and the best adsorption effect was achieved in neutral and alkaline environments. After five cycles of regeneration and reuse, the COF-NH2 microspheres retained their good adsorption efficiency for PFCs. The adsorption mechanism was mainly attributed to the synergistic effect of hydrogen bonding and hydrophobic interactions between COF-NH2 and the PFCs. The extraction efficiencies of the microspheres toward five PFCs (perfluorobutyric acid, perfluorovaleric acid, perfluorohexanoic acid, perfluorooctanoic acid, and perfluorononanoic acid) in tap and Pearl River water samples were between 91.76% and 98.59%, with relative standard deviations (RSDs) (n=3) varying from 0.82% to 3.8%; these findings indicate that the obtained COF-NH2 is promising for the extraction of PFCs from complex water samples. Given their uniform size distribution, high thermal stability, good adsorption performance, and reusability, the novel spherical COF-NH2 materials developed in this study may be used as solid-phase extraction materials or filled into liquid chromatographic columns for the enrichment, separation, and detection of PFCs in complex samples.

"Two-in-one" dual-function luminescent MOF hydrogel for onsite ultra-sensitive detection and efficient enrichment of radioactive uranium in water.

In consideration of the severe hazards of radioactive uranium pollution and the growing demand of uranium resources, the novel sensor/adsorbent composite was creatively developed to integrate the dual functions for on-site detection of uranium contamination and efficient recovery of uranium resources. By hybridizing the luminescent 3D terbium (III) metal-organic framework (Tb-MOF) with sodium alginate (SA) gel using terbium (III) as cross-linker, the Tb-MOF/Tb-AG was fabricated with multi-luminescence centers and sufficient binding sites for uranium. Notably, the ultra-high sensitivity with detection limit as low as 1.2 ppt was achieved, which was 4 orders of magnitude lower than the uranium contamination standard in drinking water (USEPA) and even comparable to the sensitivity of the ICP-MS. Furthermore, the very wide quantification range (1.0 ×10-9-5.0 ×10-4 mol/L), remarkable adsorption capacity (549.0 mg/g) and outstanding anti-interference ability have been achieved without sophisticated sample preparation procedures. Applied in complex natural water samples from Uranium Tailings and the Pearl River, this method has shown good detection accuracy. The ultra high sensitivity and great adsorption capacity for uranium could be ascribed to the synergistic coordination, hydrogen bonding and ion exchange between uranium and Tb-MOF/Tb-AG. The mechanisms were explored by infrared spectroscopy, batch experiments, X-ray photoelectron studies and energy dispersive spectroscopic studies. In addition, the Tb-MOF/Tb-AG can be reused for uranium adsorption.

Novel biocompatible and sensitive visual sensor based on aggregation-induced emission for on-site detection of radioactive uranium in water and live cell imaging.

In consideration of the severe hazards of radioactive uranium pollution, the rapid assessment of uranium in field and in vivo are urgently needed. In this work a novel biocompatible and sensitive visual fluorescent sensor based on aggregation-induced emission (AIE) was designed for onsite detection of UO22+ in complex environmental samples, including wastewater from Uranium Plant, river water and living cell. The AIE-active sensor (named as TPA-SP) was prepared with a "bottom-up" strategy by introducing a trianiline group (TPA) with a single-bond rotatable helix structure into the salicylaldehyde Schiff-base molecule. The photophysical properties, cytotoxicity test, recognition mechanism and the analytical performance for the detection of UO22+ in actual water samples and cell imaging were systematically investigated. TPA-SP exhibited high sensitivity and selectivity toward UO22+ as well as outstanding anti-interference ability against large equivalent of different ions in a wide effective pH range. A good linear relationship in the UO22+ concentration range of 0.05-1 µM was obtained with a low limit of detection (LOD) of 39.4 nM (9.38 ppb) for uranium detection. The prepared visual sensor showed great potential for fast risk assessment of uranium pollution in environmental systems. In addition, our results also indicated that the TPA-SP exhibited very low cytotoxicity in cells and demonstrated great potential for uranium detection in vivo.

[Functional characterization and enzymatic properties of flavonoid glycosyltransferase gene CtUGT49 in Carthamus tinctorius].

Carthami Flos, as a traditional blood-activating and stasis-resolving drug, possesses anti-tumor, anti-inflammatory, and immunomodulatory pharmacological activities. Flavonoid glycosides are the main bioactive components in Carthamus tinctorius. Glycosyltransferase deserves to be studied in depth as a downstream modification enzyme in the biosynthesis of active glycoside compounds. This study reported a flavonoid glycosyltransferase CtUGT49 from C. tinctorius based on the transcriptome data, followed by bioinformatic analysis and the investigation of enzymatic properties. The open reading frame(ORF) of the gene was 1 416 bp, encoding 471 amino acid residues with the molecular weight of about 52 kDa. Phylogenetic analysis showed that CtUGT49 belonged to the UGT73 family. According to in vitro enzymatic results, CtUGT49 could catalyze naringenin chalcone to the prunin and choerospondin, and catalyze phloretin to phlorizin and trilobatin, exhibiting good substrate versatility. After the recombinant protein CtUGT49 was obtained by hetero-logous expression and purification, the enzymatic properties of CtUGT49 catalyzing the formation of prunin from naringenin chalcone were investigated. The results showed that the optimal pH value for CtUGT49 catalysis was 7.0, the optimal temperature was 37 ℃, and the highest substrate conversion rate was achieved after 8 h of reaction. The results of enzymatic kinetic parameters showed that the K_m value was 209.90 µmol·L~(-1) and k_(cat) was 48.36 s~(-1) calculated with the method of Michaelis-Menten plot. The discovery of the novel glycosyltransferase CtUGT49 is important for enriching the library of glycosylation tool enzymes and provides a basis for analyzing the glycosylation process of flavonoid glycosides in C. tinctorius.

Synthesis and application of novel N, Si-carbon dots for the ratiometric fluorescent monitoring of the antibiotic balofloxacin in tablets and serum.

A ratiometric fluorescent probe with blue-emission fluorescence based on N, Si-doped carbon dots (N, Si-CDs) for the detection of balofloxacin (BLFX) was synthesized by simple one-pot hydrothermal carbonization using methotrexate and 3-aminopropyltriethoxysilane (APTES) as carbon materials. The obtained N, Si-CDs showed dual-emission band fluorescence characterization at 374 nm and 466 nm. Furthermore, the synthesized N, Si-CD probe exhibited evidence of ratiometric fluorescence emission characteristics (F 466/F 374) toward BLFX along with a decrease in fluorescence intensity at 374 nm and an increase in fluorescence intensity at 466 nm. Based on this probe, a highly sensitive and fast detection method for the analysis of BLFX has been established with a linear range of 1-60 µM and a low detection limit of 0.1874 µM, as well as a rapid response time of 5.0 s. The developed assay has also been successfully applied for the detection of BLFX in tablets and rat serum.

[Allergenic risk analysis of street trees of urban alleys in Qingyang District, Chengdu, China]. / æˆéƒ½é’ç¾ŠåŒºèƒŒè¡—å°å··è¡Œé“æ ‘å­¢ç²‰è‡´æ•é£Žé™©åˆ†æž.

We examined the pollen allergy risk of street trees in urban alleys, with 410 urban alleys in Qingyang District, Chengdu as an example. On the basis of recording the characteristics of street trees, we calculated the index of allergenicity of urban green zones (IUGZA) values and overlay the regional population density map, and finally obtained the pollen allergy risk map of urban alleys in Qingyang District. The results showed that there were 32461 street trees in 410 urban alleys, belonging to 27 families, 41 genera, and 52 species. The distribution of tree species was extremely uneven, with excessive plantation of Ficus concinna (31.8%), Ginkgo biloba (12.9%) and Cinnamomum camphora (8.5%). The risk of pollen allergy in urban alleys was high, with an average IUGZA value of 2.61 and spring as the primary risk season. Among them, 175 alleys were at the most low allergy degree (IUGZA=0-1), 174 alleys at low degree of allergy (IUGZA=1-5), and 6 alleys at extremely high risk of allergy (IUGZA=15-20). Results of correlation analysis showed that mean tree height and canopy-to-street area ratio were the key factors affecting IUGZA of street trees in urban alleys. After superimposing the population density map, Shaocheng Street, Caoshi Street, Xiyuhe Street, Funan Street, and Supo Street had a high risk of pollen allergy.

A Ratiometric Fiber Optic Sensor Based on CdTe QDs Functionalized with Glutathione and Mercaptopropionic Acid for On-Site Monitoring of Antibiotic Ciprofloxacin in Aquaculture Water.

A ratiometric fluorescence fiber-optical sensor system (RFFS) merging a Y-type optical fiber spectrometer and CdTe QDs composite functionalized with glutathione and mercaptopropionic acid (GMPA@CdTe-QDs) for highly selective and on-site detection of ciprofloxacin (CIP) in environmental water samples was designed. Our preliminary results suggested that the red fluorescence of the synthesized GMPA@CdTe-QDs was effectively quenched by CIP. Based on this, the RFFS/GMPA@CdTe-QDs system was successfully fabricated and used for highly selective and rapid detection of CIP on site in the concentration range from 0 to 45 µM with the detection limit of 0.90 µM. The established method exhibited good interference resistance to the analogues of CIP and provided a great potential platform for real-time detection of CIP residues in environmental water. In addition, the fluorescence quenching mechanism of GMPA@CdTe-QDs by CIP was also investigated by means of temperature effect, fluorescence lifetime, ultraviolet (UV) visible absorption, and fluorescent spectra. Our results suggested clearly that the red fluorescence of GMPA@CdTe-QDs was quenched by CIP via the photoinduced electron-transfer (PET) mode.

A novel fluorescence ratio probe based on dual-emission carbon dots for highly selective and sensitive detection of chlortetracycline and cell imaging.

The novel dual-emission carbon dots (DECDs) for highly selective and sensitive recognition of chlortetracycline (CTC) and cell imaging were synthesized successfully by one-step synthesis. The obtained DECDs possessed two fluorescence peaks (345 nm and 450 nm) and showed specific response to CTC, resulting in a decrease in fluorescence intensity at 345 nm, a blue shift, and an increase in fluorescence intensity at 450 nm. The obtained DECDs exhibited highly selective response to CTC and not to its analogues, such as tetracycline, doxycycline, and oxytetracycline. Thus, an excellent ratiometric probe for the detection of CTC was fabricated successfully and used for the detection of CTC in real samples with the detection limit (LOD) of 16.45 nM. More importantly, the DECDs were used for quantitative detection of CTC in living cells, which demonstrated excellent biocompatibility and broad prospects in biomedicine application. Finally, the excellent selectivity of DECDs toward CTC was attributed to the FRET mechanism and the formation of complexes.

[Tissue culture of safflower and analysis of secondary metabolites in suspension cells].

Safflower(Carthamus tinctorius), a valuable traditional Chinese medicinal plant, has attracted much attention in recent years. This study established a stable tissue culture system of safflower and analyzed the chromatogram of its secondary metabolites, providing high-quality experimental materials for further research on natural products in safflower. The calluses were established from the safflower seeds germinated in a sterile environment, and then they were differentiated into the aseptic seedlings, or cultured to obtain suspension cells in liquid medium. The ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF-MS), Progenesis QI, and principal component analysis(PCA) were used to detect and analyze the secondary metabolites in the suspension cells before and after induction with different elicitors(methyl jasmonate, silver nitrate, salicylic acid and yeast extract). A total of 23 secondary metabolites including flavonoids, phenylpropanoids, alkaloids, fatty acids and aromatic glycosides were detected in safflower suspension cells. In response to the four elicitors, 11 compounds showed increased or decreased relative content. The results indicate that different elicitors have various effects on the accumulation of secondary metabolites in safflower suspension cells, and yeast extract shows more obvious positive induction. Therefore, different elicitors may play a role in the expression of related genes in the biosynthetic pathway of specific secondary metabolites. The results facilitate the discovery of targeted elicitors and the large-scale production of valuable secondary metabolites in the future.

A bean common mosaic virus-resistance gene in the soybean variant V94-5152 was mapped to the Rsv4 locus conferring resistance to soybean mosaic virus.

KEY MESSAGE: In the soybean variant V94-5152, a BCMV-resistance gene was mapped near to the region of SMV-resistance Rsv4 locus, raising a possibility that V94-5152 may rely on Rsv4 locus to resist against both SMV and BCMV. Both Soybean mosaic virus (SMV) and Bean common mosaic virus (BCMV) can induce soybean mosaic diseases, but few studies have explored soybean resistance against BCMV so far. In this study, V94-5152, a soybean variant resistant to BCMV and SMV, was crossed with a susceptible cultivar, Williams 82 to map the resistance gene. By inoculating 292 F2 individuals with a BCMV isolate HZZB011, a segregation ratio of 3 resistant: 1 susceptible was observed, suggesting that V94-5152 possesses a single-dominant resistance gene against BCMV-HZZB011. Bulk segregation analysis (BSA) then revealed that the resistance gene is closely linked to BARCSOYSSR_02_0617, a simple sequence repeat (SSR) marker on chromosome 2. Genotyping neighboring SSR markers among the 292 F2 individuals enabled us to draw a genetic linkage map, which indicated that the BCMV-resistance gene is located 0.2 cM downstream of BARCSOYSSR_02_0617. Amplification and sequencing ten candidate genes (Glyma02g121300 to Glyma02g122200) around this marker then revealed four genes containing nonsynonymous changes or indels. Also, this location is near to the recently cloned SMV-resistance Rsv4 locus from the cultivar Peking. By obtaining ten more sequences of Rsv4 locus from cultivated and wild soybean materials, we further investigated the variation and evolutionary patterns of this virus-resistance locus. It was evident that positive selections had been acting on this locus, with one critical amino acid change (R55P) shared by all resistance soybeans tested.

Molecular cloning and functional characterization of multiple ApOSCs from Andrographis paniculata.

Triterpenoids have been described in Andrographis paniculata. Oleanolic acid exhibits high biological activity and is widely used in the clinic, and ß-sitosterol not only has good biological activity but also plays an important physiological role in plants. However, analysis of the biosynthetic pathway of triterpenoids in Andrographis paniculata has not been reported. Here, we provide the first report of the isolation and identification of nine 2, 3-oxidosqualene cyclases (ApOSC3 to ApOSC11) from A. paniculata. The results showed that ApOSC4 represented a monofunctional synthase that could convert 2, 3-oxidosqualene to ß-amyrin. ApOSC5 as a bifunctional 2, 3-oxidosqualene cyclases, could transfer 2, 3-oxidosqualene to ß-amyrin and α-amyrin. ApOSC6 to ApOSC8 composed the multifunctional 2, 3-oxidosqualene cyclases that could convert 2, 3-oxidosqualene to ß-amyrin, α-amyrin and one or two undetermined triterpenoids. This study provides a better understanding of the biosynthetic pathway of triterpenoids in A. paniculata, and the discovery of multifunctional 2, 3-oxidosqualene cyclases ApOSC5 to ApOSC8 of the facilitates knowledge of the compounds diversity in A. paniculata.

[Discussion on research idea of quality marker of Salvia miltiorrhiza based on biosynthetic pathway of tanshinone compounds].

Based on the theory of Q-marker, the hairy root of Salvia miltiorrhiza and S. miltiorrhiza in many provinces were studied. The relative expressions of SmCPS, SmKSL and CYP76AH1 genes in hairy roots were detected by real-time fluorescence quantitative PCR and the contents of tanshinoneⅡ_A, cryptotanshinone, tanshinoneⅠ, 1,2-dihydrotanshinone, ferruginol and miltiradiene were detected by UPLC and GC-MS, respectively. Statistical analysis shows as fllows: in the hairy root of S. miltiorrhiza, the content of miltiradiene and ferruginol is positively correlated with the content of tanshinone compounds in the downstream, and the relative expression of important genes in the biosynthetic pathway of tanshinone can reflect the content of tanshinone compounds to a certain extent; in many provinces of S. miltiorrhiza, the content of ferruginol and tanshinone compounds can also be found that there is a positive correlation between the contents. Based on the biosynthetic pathway of tanshinone compounds, which is a special index component in S. miltiorrhiza, this study focused on the important relationship between the upstream gene, the middle intermediate compound and the downstream tanshinone compound content of the biosynthetic pathway, and explored the possible research ideas of improving the quality marker system of S. miltiorrhiza, and then provided the possible research ideas for understanding and studying the quality marker of traditional Chinese medicine from the biosynthetic pathway.

[Effect of GR24 on accumulation of diterpenoids in Tripterygium wilfordii suspension cells].

Terpenoids are main bioactive components in Tripterygium wilfordii,but the contents of some terpenoids are relatively low. In order to provide scientific evidence for the regulation of terpenoids in T. wilfordii,this research explored the effect of GR24 on accumulations of four diterpenoids( triptolide,tripterifordin,triptophenolide,and triptinin B) in T. wilfordii suspension cells by biological technology and UPLC-QQQ-MS/MS. The results indicated that 100 µmol·L-1 GR24 inhibited the accumulations of triptolide,tripterifordin,triptophenolide,and triptinin B to different degrees. Compared with the control group,the contents of 4 diterpenoids( in the induced group) were down to 96.59%,63.80%,61.02% and 33.59% in 240 h,respectively. Among them,the accumulation of triptinin B iswas significantly inhibited. In addition,the key time point of inhibitory effect was 120 h after induction with GR24 in some diterpenoids. This is the first systematic study focusing on the effect of GR24 on the accumulations of diterpenoids in T. wilfordii suspension cells. The dynamic accumulation ruleregularity of four diterpenoids after induced by GR24 was summarized,which laid a foundation for further study on the chemical response mechanism of terpenoids to GR24.

[Bioinformatics and tissue distribution analysis of Tripterygium wilfordii CYP450].

Cytochrome P450 family is a kind of biocatalyst widely existing in nature. It has many functions such as catalyzing the biosynthesis of plant secondary metabolites and regulating phytoremediation. Based on the analysis of proteome data of Tripterygium wilfordii,the CYP450 gene of T. wilfordii was preliminarily analyzed and predicted by various bioinformatics methods. The results showed that after the expression of T. wilfordii suspension cells was induced by methyl jasmonate,the proteomic data of T. wilfordii were obtained and analyzed,and 10 CYP450 proteins of T. wilfordii were finally screened out. By analyzing the phylogenetic tree constructed with CYP450 gene of Arabidopsis family,the 10 CYP450 proteins were clustered into 6 different CYP450 families. The physical and chemical properties of CYP450 proteins in different families were different. The secondary structure of CYP450 proteins was mainly composed of irregular curls. Eight subcellular localization results of CYP450 proteins were chloroplasts and the rest were plastids. Subsequently,the conserved domains( heme active sites) shared by CYP450 genes were found by analyzing the results of multiple sequence alignment. Finally,by analyzing the transcriptome data of T. wilfordii,the expression distribution of T. wilfordii in different tissues was preliminarily confirmed,which verified its correlation with the biosynthesis of active components of T. wilfordii,and provided important genetic resources for the analysis of biosynthesis pathway of active components of T. wilfordii.

A bean common mosaic virus (BCMV)-resistance gene is fine-mapped to the same region as Rsv1-h in the soybean cultivar Suweon 97.

KEY MESSAGE: In the soybean cultivar Suweon 97, BCMV-resistance gene was fine-mapped to a 58.1-kb region co-localizing with the Soybean mosaic virus (SMV)-resistance gene, Rsv1-h raising a possibility that the same gene is utilized against both viral pathogens. Certain soybean cultivars exhibit resistance against soybean mosaic virus (SMV) or bean common mosaic virus (BCMV). Although several SMV-resistance loci have been reported, the understanding of the mechanism underlying BCMV resistance in soybean is limited. Here, by crossing a resistant cultivar Suweon 97 with a susceptible cultivar Williams 82 and inoculating 220 F2 individuals with a BCMV strain (HZZB011), we observed a 3:1 (resistant/susceptible) segregation ratio, suggesting that Suweon 97 possesses a single dominant resistance gene against BCMV. By performing bulked segregant analysis with 186 polymorphic simple sequence repeat (SSR) markers across the genome, the resistance gene was determined to be linked with marker BARSOYSSR_13_1109. Examining the genotypes of nearby SSR markers on all 220 F2 individuals then narrowed down the gene between markers BARSOYSSR_13_1109 and BARSOYSSR_13_1122. Furthermore, 14 previously established F2:3 lines showing crossovers between the two markers were assayed for their phenotypes upon BCMV inoculation. By developing six more SNP (single nucleotide polymorphism) markers, the resistance gene was finally delimited to a 58.1-kb interval flanked by BARSOYSSR_13_1114 and SNP-49. Five genes were annotated in this interval of the Williams 82 genome, including a characteristic coiled-coil nucleotide-binding site-leucine-rich repeat (CC-NBS-LRR, CNL)-type of resistance gene, Glyma13g184800. Coincidentally, the SMV-resistance allele Rsv1-h was previously mapped to almost the same region, thereby suggesting that soybean Suweon 97 likely relies on the same CNL-type R gene to resist both viral pathogens.

Fine mapping of the Rsv1-h gene in the soybean cultivar Suweon 97 that confers resistance to two Chinese strains of the soybean mosaic virus.

KEY MESSAGE: The Rsv1 - h gene in cultivar Suweon 97, which confers resistance to SMVs, was mapped to a 97.5-kb location (29,815,195-29,912,667 bp on chromosome 13) in the Rsv1 locus, thereby providing additional insights into the molecular nature underlying variations in resistance alleles in this particular locus. Soybean mosaic virus (SMV) is a well-known devastating pathogen of soybean (Glycine max (L.) Merrill.) causing significant yield losses and seed quality deterioration. A single dominant allele, Rsv1-h, which confers resistance to multiple SMV strains, was previously reported in the cultivar Suweon 97, but its exact location is unknown. In the present study, Suweon 97 was crossed with a SMV-sensitive cultivar, Williams 82. Inoculating 267 F 2 individuals with two Chinese SMV strains (SC6-N and SC7-N) demonstrated that one single dominant gene confers SMV resistance. Another 1,150 F 2 individuals were then screened for two simple sequence repeat (SSR) markers (BARCSOYSSR_13_1103 and BARCSOYSSR_13_1187) that flank the Rsv1 locus. Seventy-four recombinants were identified and 20 additional polymorphic SSR markers within the Rsv1 region were then employed in genotyping these recombinants. F 2:3 and F 3:4 recombinant lines were also inoculated with SC6-N and SC7-N to determine their phenotypes. The final data revealed that in Suweon 97, the Rsv1-h gene that confers resistance to SC6-N and SC7-N was flanked by BARCSOYSSR_13_1114 and BARCSOYSSR_13_1115, two markers that delimit a 97.5-kb region in the reference Williams 82 genome. In such region, eight genes were present, of which two, Glyma13g184800 and Glyma13g184900, encode the characteristic CC-NBS-LRR type of resistance gene and were considered potential candidates for Rsv1-h.

Soybean Cyst Nematode Resistance Emerged via Artificial Selection of Duplicated Serine Hydroxymethyltransferase Genes.

A major soybean (Forrest cultivar) quantitative trait locus (QTL) gene, Rhg4, which controls resistance to soybean cyst nematodes (SCN), encodes the enzyme serine hydroxylmethyltransferase (SHMT). The resistant allele possesses two critical missense mutations (P130R and N358Y) compared to that of the sensitive allele, rhg4. To understand the evolutionary history of this gene, sequences of 117 SHMT family members from 18 representative plant species were used to reconstruct their phylogeny. According to this phylogeny, the plant SHMT gene family can be divided into two groups and four subgroups (Ia, Ib, IIa, and IIb). Belonging to the Subgroup Ia lineage, the rhg4 gene evolved from a recent duplication event in Glycine sp.. To further explore how the SCN-resistant allele emerged, both the rhg4 gene and its closest homolog, the rhg4h gene, were isolated from 33 cultivated and 68 wild soybean varieties. The results suggested that after gene duplication, the soybean rhg4 gene accumulated a higher number of non-synonymous mutations than rhg4h. Although a higher number of segregating sites and gene haplotypes were detected in wild soybeans than in cultivars, the SCN-resistant Rhg4 allele (represented by haplotype 4) was not found in wild varieties. Instead, a very similar allele, haplotype 3, was observed in wild soybeans at a frequency of 7.4%, although it lacked the two critical non-synonymous substitutions. Taken together, these findings support that the SCN-resistant Rhg4 allele likely emerged via artificial selection during the soybean domestication process, based on a SCN-sensitive allele inherited from wild soybeans.

Identification of Arbuscular Mycorrhiza (AM)-Responsive microRNAs in Tomato.

A majority of land plants can form symbiosis with arbuscular mycorrhizal (AM) fungi. MicroRNAs (miRNAs) have been implicated to regulate this process in legumes, but their involvement in non-legume species is largely unknown. In this study, by performing deep sequencing of sRNA libraries in tomato roots and comparing with tomato genome, a total of 700 potential miRNAs were predicted, among them, 187 are known plant miRNAs that have been previously deposited in miRBase. Unlike the profiles in other plants such as rice and Arabidopsis, a large proportion of predicted tomato miRNAs was 24 nt in length. A similar pattern was observed in the potato genome but not in tobacco, indicating a Solanum genus-specific expansion of 24-nt miRNAs. About 40% identified tomato miRNAs showed significantly altered expressions upon Rhizophagus irregularis inoculation, suggesting the potential roles of these novel miRNAs in AM symbiosis. The differential expression of five known and six novel miRNAs were further validated using qPCR analysis. Interestingly, three up-regulated known tomato miRNAs belong to a known miR171 family, a member of which has been reported in Medicago truncatula to regulate AM symbiosis. Thus, the miR171 family likely regulates AM symbiosis conservatively across different plant lineages. More than 1000 genes targeted by potential AM-responsive miRNAs were provided and their roles in AM symbiosis are worth further exploring.

Effect of ear-acupoint pressing and Ear Apex (HX6,7) bloodletting on haemorheology in chloasma patients with Gan depression pattern.

OBJECTIVE: To explore the therapeutical effect of ear-acupoint pressing combined with Ear Apex (HX6,7) bloodletting on haemorheology in chloasma patients with Gan (Liver) depression pattern. METHODS: A total of 180 chloasma patients were randomly assigned to three groups, 60 cases in each. Patients in the earacupuncture (EA) group were treated with ear-acupoint pressing combined with Ear Apex (HX6,7) bloodletting; vitamins C and E were put into practice in the Western medicine (WM) group together with 0.025% tretinoin cream for local external application; patients in the placebo group were treated with urea-cream by external use, while 30 healthy volunteers were in the control group. After a treatment course of 2 months, the changes of haemorheology, injury skin area, colour score and symptom score before and after the treatment were observed. RESULTS: There was no significant difference on whole blood reduced viscosity (high shear, medium shear, and low shear), erythrocyte aggregation index, hematocrit, plasma viscosity among the four groups (F =2.65, P>0.05). Compared with those before treatment, the whole blood viscosity (high shear) and whole blood reduced viscosity (high shear) after treatment in the EA group, the WM group and the placebo group were with no statistical significance (P>0.05). The injury skin area and colour score after treatment were significantly lower than those before treatment in the EA group and the WM group (P<0.05), while there was no significant difference in placebo group (P>0.05). Clinical symptoms of the EA group were obviously improved after the 2-month treatment, which was significantly different compared with those before treatment (P<0.05), there was significant difference compared with those of WM group and placebo group (P<0.05). CONCLUSION: There was no significant difference on haemorheology index between healthy people and chloasma patients without angionosis, cerebrovascular disease, hematopathy, metabolic disease or any other organic disease. Ear-acupoint pressing combined with Ear Apex (HX6,7) bloodletting can effectively improve concurrent symptoms, lighten chloasma and lower chloasma area in patients accompanied by Gan depression.

The evolution of soybean mosaic virus: An updated analysis by obtaining 18 new genomic sequences of Chinese strains/isolates.

Soybean mosaic virus (SMV) is widely recognized as a highly damaging pathogen of soybean, and various strains/isolates have been reported to date. However, the pathogenic differences and phylogenetic relationships of these SMV strains/isolates have not been extensively studied. In the present work, by first obtaining 18 new genomic sequences of Chinese SMV strains/isolates and further compiling these with available data, we have explored the evolution of SMV from multiple aspects. First, as in other potyviruses, recombination has occurred frequently during SMV evolution, and a total of 32 independent events were detected. Second, using a maximum-likelihood method and removing recombinant fragments, a phylogeny covering 83 SMV sequences sampled from all over the world was reconstructed and the results showed four separate SMV clades, with clade I and II recovered for the first time. Third, the population structure analysis of SMV revealed significant genetic differentiations between China and two other countries (Korea and U.S.A.). Fourth, certain SMV-encoded genes, such as P1, HC-Pro and P3, exhibited higher non-synonymous substitution rate (dN) than synonymous substitution rate (dS), indicating that positive selection has influenced these genes. Finally, four Chinese SMV strains/isolates were selected for inoculation of both USA and Chinese differential soybean cultivars, and their pathogenic phenotypes were significantly different from that of the American strains. Overall, these findings have further broadened our understanding on SMV evolution, which would assist researchers to better deal with this harmful virus.