Identification, pathogenicity, and fungicide sensitivity of Eutiarosporella dactylidis associated with leaf blight on maize in China

Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.

Limited Sea Surface Temperature Cooling Due to the Barrier Layer Promoting Super Typhoon Mangkhut(2018)

This study investigates the impact of the salinity barrier layer(BL)on the upper ocean response to Super Typhoon Mangkhut(2018)in the western North Pacific.After the passage of Mangkhut,a noticeable increase(~0.6 psu)in sea surface salinity and a weak decrease(<1℃)in sea surface temperature(SST)were observed on the right side of the typhoon track.Mangkhut-induced SST change can be divided into the three stages,corresponding to the variations in BL thickness and SST before,during,and after the passage of Mangkhut.During the pre-typhoon stage,SST slightly warmed due to the entrainment of BL warm water,which suppressed the cooling induced by surface heat fluxes and horizontal advection.During the forced stage,SST cooling was controlled by entrainment,and the preexisting BL reduced the total cooling by 0.89℃ d-1,thus significantly weakening the overall SST cooling induced by Mangkhut.During the relaxation stage,the SST cooling was primarily caused by the entrainment.Our results indicate that a preexisting BL can limit typhoon-induced SST cooling by suppressing the entrainment of cold thermocline water,which contributed to Mangkhut becoming the strongest typhoon in 2018.

遗传漂变教学方法刍议

遗传漂变是影响群体遗传平衡的4个重要因素之一。因为它的作用形式不如突变、选择、迁移这3个因素那么直观易懂,所以在理解和掌握上存在较大的困难。尤其目前国内外教材中关于遗传漂变内容的介绍系统性不足,要么过于粗略,要么完全忽视了二项式定理这样的数学基础,造成了遗传漂变学习长期不到位的困难局面。本文总结得出遗传漂变的5个基本属性,即固有性、普遍性、随机性、无方向性、有规律性。进而从遗传漂变的遗传基础是雌雄配子的自由组合出发,指出抽样误差属性是遗传漂变固有的本质特征,并循序渐进地从N=1这样仅仅由1个个体组成的极端小群体出发,推演出遗传漂变随着群体变大而影响减弱的性质,通过二项式定理数学模型、二项分布的特点、以及计算机模拟结果,形象直观地展示遗传漂变的作用,助力遗传漂变教学。

粗糙脉孢菌7种子囊型归类教学探究

遗传分析是本科遗传学教学的重要内容,四分子分析是真菌类遗传分析的独特方式,其中的粗糙脉孢菌顺序四分子分析不仅可以研究基因与着丝粒间的重组、基因间的重组,而且还可以精细研究同源染色体非姊妹染色单体之间的交换形式,是深入理解交换重组分子机制的重要遗传学研究材料。对此,教材中已有详尽的介绍。美中不足的是,中外教科书和相关专业期刊中缺乏对顺序四分子两基因连锁分析中7种基本子囊型归纳方法的具体介绍,令相关内容的学习留下疑惑。本文从顺序四分子两基因连锁遗传分析过程中涉及的3种四分子类型(PD、NPD和T)与两基因4种分离时期组合(ⅠⅠ,ⅡⅡ,ⅠⅡ,ⅡⅠ)的相互关系入手,设计表格,直观展现了二者的12种可能组合结果(3×4=12),并应用直观的对错符号(√、×),同时结合表后的3项分析,排除了其中的5种组合形式,最终归纳得到7种基本子囊型。本文提供了7种基本子囊型具体的归纳分析方法,解决了相关教学内容的论述不足问题,以期为真菌类顺序四分子遗传分析的教学提供帮助。

Microphysical Characteristics of Precipitation during Pre-monsoon,Monsoon, and Post-monsoon Periods over the South China Sea

Raindrop size distribution (RSD) characteristics over the South China Sea (SCS) are examined with onboard Parsivel disdrometer measurements collected during marine surveys from 2012 to 2016. The observed rainfall is divided into premonsoon, monsoon, and post-monsoon periods based on the different large-scale circumstances. In addition to disdrometer data, sounding observation, FY-2E satellite, SPRINTARS (Spectral Radiation-Transport Model for Aerosol Species), and NCEP reanalysis datasets are used to illustrate the dynamical and microphysical characteristics associated with the rainfall in different periods. Significant variations have been observed in respect of raindrops among the three periods. Intercomparison reveals that small drops (D < 1 mm) are prevalent during pre-monsoon precipitation, whereas medium drops (1?3 mm) are predominant in monsoon precipitation. Overall, the post-monsoon precipitation is characterized by the least concentration of raindrops among the three periods. But, several large raindrops could also occur due to severe convective precipitation events in this period. Classification of the precipitation into stratiform and convective regimes shows that the lg(Nw) value of convective rainfall is the largest (smallest) in the pre-monsoon (post-monsoon) period, whereas the Dm value is the smallest (largest) in the pre-monsoon (post-monsoon) period. An inversion relationship between the coefficient A and the exponential b of the Z?R relationships for precipitation during the three periods is found. Empirical relations between Dm and the radar reflectivity factors at Ku and Ka bands are also derived to improve the rainfall retrieval algorithms over the SCS. Furthermore, the possible causative mechanisms for the significant RSD variability in different periods are also discussed with respect to warm and cold rain processes, raindrop evaporation, convective activities, and other meteorological factors.

Identification and fine mapping of two blast resistance genes in rice cultivar 93-11

Rice blast, caused by Magnaporthe oryzae, is a major disease of rice almost worldwide. The Chinese indica cultivar 93-11 is resistant to numerous isolates of the blast fungus in China, and can be used as broad-spectrum resistance resource, particularly in japonica rice breeding programs. In this study, we identified and mapped two blast resistance genes, Pi60(t) and Pi61(t), in cv. 93-11 using F2 and F3 populations derived from a cross between the susceptible cv. Lijiangxintuanheigu(LTH) and resistant cv. 93-11 and inoculated with M. oryzae isolates from different geographic origins. Pi60(t) was delimited to a 274 kb region on the short arm of chromosome 11, flanked by InDel markers K1-4 and E12 and cosegregated with InDel markers B1 and Y10. Pi61(t) was mapped to a 200 kb region on the short arm(near the centromere) of chromosome 12, flanked by InDel markers M2 and S29 and cosegregating with InDel marker M9. In the 274 kb region of Pi60(t), 93-11 contains six NBS-LRR genes including the two Pia/ PiCO39 alleles(BGIOSGA034263 and BGIOSGA035032) which are quite close to the two Pia/ PiCO39 alleles(SasRGA4 and SasRGA5) in Sasanishiki and CO39, with only nine amino acids differing in the protein sequences of BGIOSGA035032 and SasRGA5. In the 200 kb region of Pi61(t), 93-11 contains four NBS-LRR genes, all of which show high identities in protein sequence with their corresponding NBS-LRR alleles in susceptible cv. Nipponbare. Comparison of the response spectra and physical positions between the target genes and other R genes in the same chromosome regions indicated that Pi60(t) could be Pia/PiCO39 or its allele, whereas Pi61(t) appears to be different from Pita, Pita-2, Pi19(t), Pi39(t) and Pi42(t) in the same R gene cluster. DNA markers tightly linked to Pi60(t) and Pi61(t) will enable marker-assisted breeding and map-based cloning.

The R2R3-type MYB transcription factor MdMYB90-like is responsible for the enhanced skin color of an apple bud sport mutant

The anthocyanin content in apple skin determines its red coloration,as seen in a Fuji apple mutant.Comparative RNA-seq analysis was performed to determine differentially expressed genes at different fruit development stages between the wild-type and the skin color mutant.A novel R2R3-MYB transcription factor,MdMYB90-like,was uncovered as the key regulatory gene for enhanced coloration in the mutant.The expression of MdMYB90-like was 21.3 times higher in the mutant.MdMYB90-like regulates anthocyanin biosynthesis directly through the activation of anthocyanin biosynthesis genes and indirectly through the activation of other transcription factors that activate anthocyanin biosynthesis.MdMYB90-like bound to the promoters of both structural genes(MdCHS and MdUFGT)and other transcription factor genes(MdMYB1 and MdbHLH3)in the yeast one-hybrid system,electrophoretic mobility shift assay,and dual-luciferase assay.Transgenic analysis showed that MdMYB90-like was localized in the nucleus,and its overexpression induced the expression of other anthocyanin-related genes,including MdCHS,MdCHI,MdANS,MdUFGT,MdbHLH3,and MdMYB1.The mutant had reduced levels of DNA methylation in two regions(−1183 to−988 and−2018 to−1778)of the MdMYB90-like gene promoter,which might explain the enhanced expression of the gene and the increased anthocyanin content in the mutant apple skin.

Effect of single Si_(1−x)C_(x)coating and compound coatings on the thermal conductivity and corrosion resistance of Mg-3Sn alloy

A single Si_(1−x)C_(x)coating and compound coatings were deposited on Mg-3Sn matrix alloy by magnetron sputtering method.Compound coatings included Mg or Mg/AlTi intermediates between Mg-3Sn substrate and Si_(1−x)C_(x)coating.The thermal conductivity of the Mg-3Sn alloy after coating was enhanced at room temperature.The results showed that the Mg-3Sn alloy coated with Mg/AlTi/Si_(1−x)C_(x)displayed higher thermal conductivity,its thermal conductivity after corrosion was 90.1 W/(m K)and 108.4 W/(m K)at 25℃and 100℃,respectively.Meanwhile,it was revealed that the Mg/Si_(1−x)C_(x)and Mg/AlTi/Si_(1−x)C_(x)compound coatings had nobler Ecorr and much lower i_(corr),higher Rp,compared with the bare Mg-3Sn and Mg-3Sn/Si_(1−x)C_(x)system,and improved the corrosion resistance of the magnesium substrate.

Electrochemical investigation on the film of L-cysteine self-assembled to nanoparticles on a gold electrode

The film contained L-cysteine and gold nanoparticles were provided by self-assembled monolayers (SAMs) and potentiostatic electrodeposition technology on the gold electrode. Two methods were used to study the film: In the first, cyclic voltammetry (CV) was used to inspect the functional groups of the film and the same time hydroquinone was chosen to be a probe molecule in the based solution;secondly, based on analytical technology of scanning electrochemical microscopy (SECM), the heterogeneous rate constant (keff) between solid phase (the modified electrode) and liquid phase (K3Fe(CN)6) was obtained. As a result, the better binary catalysis of hydroquinone was demonstrated and the heterogeneous rate constant (keff) is the greater at 8 h for L-cysteine self-assembled monolayers (SAMs).

Influence Caused by Harmonic and Filtering Methods of Synchronous Generator in Short-capacity System

Relative to the power grid, the short-capacity system has smaller inertia and weaker ability to bear disturbance. As a result, the synchronous generator in short-capacity system will be greatly influenced by harmonic. To reveal how harmonic influence the generator, this article analyzed how harmonic current will influence the output voltage. Deduced a formula that can describe the electromagnetic torque pulsation brought by the theory of Instantaneous Power, which can explain why generator’s shaft vibrates. Then this article evaluated the applicability of current filtering methods in view of characteristics of the small capacity of the system. As a result, it was demonstrated that active filtering method is best suited for small capacity system. At last, it conducted the experiment that diesel generator set supply power to non-liner load to demonstrate the conclusion of theoretical analysis.

Surface modification strategies to reinforce the soft tissue seal at transmucosal region of dental implants

Soft tissue seal around the transmucosal region of dental implants is crucial for shielding oral bacterial invasion and guaranteeing the long-term functioning of implants.Compared with the robust periodontal tissue barrier around a natural tooth,the peri-implant mucosa presents a lower bonding efficiency to the transmucosal region of dental implants,due to physiological structural differences.As such,the weaker soft tissue seal around the transmucosal region can be easily broken by oral pathogens,which may stimulate serious inflammatory responses and lead to the development of peri-implant mucositis.Without timely treatment,the curable peri-implant mucositis would evolve into irreversible peri-implantitis,finally causing the failure of implantation.Herein,this review has summarized current surface modification strategies for the transmucosal region of dental implants with improved soft tissue bonding capacities(e.g.,improving surface wettability,fabricating micro/nano topographies,altering the surface chemical composition and constructing bioactive coatings).Furthermore,the surfaces with advanced soft tissue bonding abilities can be incorporated with antibacterial properties to prevent infections,and/or with immunomodulatory designs to facilitate the establishment of soft tissue seal.Finally,we proposed future research orientations for developing multifunctional surfaces,thus establishing a firm soft tissue seal at the transmucosal region and achieving the long-term predictability of dental implants.

A scaffold vaccine to promote tumor antigen cross-presentation via sustained toll-like receptor-2(TLR2)activation

Cancer vaccination holds great promise for cancer treatment,but its effectiveness is hindered by suboptimal activation of CD8+cytotoxic T lymphocytes,which are potent effectors to mediate anti-tumor immune responses.A possible solution is to switch antigen-presenting cells to present tumor antigens via the major histocompatibility complex class I(MHC-I)to CD8+T cells-a process known as cross-presentation.To achieve this goal,we develop a three-dimensional(3D)scaffold vaccine to promote antigen cross-presentation by persisted toll-like receptor-2(TLR2)activation after one injection.This vaccine comprises polysaccharide frameworks that“hook”TLR2 agonist(acGM)via tunable hydrophobic interactions and forms a 3D macroporous scaffold via click chemistry upon subcutaneous injection.Its retention-and-release of acGM enables sustained TLR2 activation in abundantly recruited dendritic cells in situ,inducing intracellular production of reactive oxygen species(ROS)in optimal kinetics that crucially promotes efficient antigen cross-presentation.The scaffold loaded with model antigen ovalbumin(OVA)or tumor specific antigen can generate potent immune responses against lung metastasis in B16-OVA-innoculated wild-type mice or spontaneous colorectal cancer in transgenic ApcMin/+mice,respectively.Notably,it requires neither additional adjuvants nor external stimulation to function and can be adjusted to accommodate different antigens.The developed scaffold vaccine may represent a new,competent tool for next-generation personalized cancer vaccination.

Multicomponent Seismic Data Reconstruction via Anti-Aliasing Vector POCS Method

0 INTRODUCTION Due to the ability to comprehensively utilize P and S wave information,multi-component seismic exploration has already played an important role in fracture detection,lithology prediction,fluid identification,etc.,and it has also become an important technology for complex reservoir exploration(Yuan et al.,2021;Stewart et al.,2003).

Modulating macrophage activities to promote endogenous bone regeneration: Biological mechanisms and engineering approaches

A coordinated interaction between osteogenesis and osteoimmune microenvironment is essential for successful bone healing.In particular,macrophages play a central regulatory role in all stages of bone repair.Depending on the signals they sense,these highly plastic cells can mediate the host immune response against the exterior signals of molecular stimuli and implanted scaffolds,to exert regenerative potency to a varying extent.In this article,we first encapsulate the immunomodulatory functions of macrophages during bone regeneration into three aspects,as sweeper,mediator and instructor.We introduce the phagocytic role of macrophages in different bone healing periods(‘sweeper’)and overview a variety of paracrine cytokines released by macrophages either mediating cell mobilisation,vascularisation and matrix remodelling(‘mediator’),or directly driving the osteogenic differentiation of bone progenitors and bone repair(‘instructor’).Then,we systematically classify and discuss the emerging engineering strategies to recruit,activate and modulate the phenotype transition of macrophages,to exploit the power of endogenous macrophages to enhance the performance of engineered bone tissue.

Cellular rejuvenation:molecular mechanisms and potential therapeutic interventions for diseases

The ageing process is a systemic decline from cellular dysfunction to organ degeneration,with more predisposition to deteriorated disorders.Rejuvenation refers to giving aged cells or organisms more youthful characteristics through various techniques,such as cellular reprogramming and epigenetic regulation.The great leaps in cellular rejuvenation prove that ageing is not a one-way street,and many rejuvenative interventions have emerged to delay and even reverse the ageing process.Defining the mechanism by which roadblocks and signaling inputs influence complex ageing programs is essential for understanding and developing rejuvenative strategies.Here,we discuss the intrinsic and extrinsic factors that counteract cell rejuvenation,and the targeted cells and core mechanisms involved in this process.Then,we critically summarize the latest advances in state-of-art strategies of cellular rejuvenation.Various rejuvenation methods also provide insights for treating specific ageing-related diseases,including cellular reprogramming,the removal of senescence cells(SCs)and suppression of senescence-associated secretory phenotype(SASP),metabolic manipulation,stem cells-associated therapy,dietary restriction,immune rejuvenation and heterochronic transplantation,etc.The potential applications of rejuvenation therapy also extend to cancer treatment.Finally,we analyze in detail the therapeutic opportunities and challenges of rejuvenation technology.Deciphering rejuvenation interventions will provide further insights into anti-ageing and ageing-related disease treatment in clinical settings.

OsPKpa_1 encodes a plastidic pyruvate kinase that affects starch biosynthesis in the rice endosperm

Pyruvate kinase （PK） is a key enzyme in glycolysis and carbon metabolism. Here, we isolated a rice （Oryza sativa） mutant, w59, with a white-core floury endosperm. Map-based cloning of w59 identified a mutation in OsPKpα1, which encodes a plastidic isoform of PK （PKp）. OsPKpα1 localizes to the amyloplast stroma in the developing endosperm, and the mutation of OsPKpα1 in w59 decreases the plastidic PK activity, resulting in dramatic changes to the lipid biosynthesis in seeds. The w59 grains were also characterized by a marked decrease in starch content. Consistent with a decrease in number and size of the w59 amyloplasts, large empty spaces were observed in the central region of the w59 endosperm, at the early grain-filling stage. Moreover, a phylogenetic analysis revealed four potential rice isoforms of OsPKp. We validated the in vitro PK activity of these OsPKps through reconstituting active PKp complexes derived from inactive individual OsPKps, revealing the heteromeric structure of rice PKps, which was further confirmed using a protein- protein interaction analysis. These findings suggest a functional connection between lipid and starch synthesis in rice endosperm amyloplasts.

The thylakoid membrane protein NTA1 is an assembly factor of the cytochrome b6f complex essential for chloroplast development in Arabidopsis

The cytochrome b_(6f)(Cyt b_(6f))complex is a multisubunit protein complex in chloroplast thylakoid membranes required for photosynthetic electron transport.Here we report the isolation and characterization of the new tiny albino 1(nta1)mutant in Arabidopsis,which has severe defects in Cyt b_(6f) accumulation and chloroplast development.Gene cloning revealed that the nta1 phenotype was caused by disruption of a single nuclear gene,NTA1,which encodes an integral thylakoid membrane protein conserved across green algae and plants.Overexpression of NTA1 completely rescued the nta1 phenotype,and knockout of NTA1 in wild-type plants recapitulated the mutant phenotype.Loss of NTA1 function severely impaired the accumulation of multiprotein complexes related to photosynthesis in thylakoid membranes,particularly the components of Cyt b_(6f).NTA1 was shown to directly interact with four subunits(Cyt b6/PetB,PetD,PetG,and PetN)of Cyt b_(6f) through the DUF1279 domain and C-terminal sequence to mediate their assembly.Taken together,our results identify NTA1 as a new and key regulator of chloroplast development that plays essential roles in assembly of the Cyt b_(6f) complex by interacting with multiple Cyt b_(6f) subunits.

Electroless deposition of Au nanoparticles on reduced graphene oxide/polyimide film for electrochemical detection of hydroquinone and catechol

An electrochemical sensor for determination of hydroquinone （HQ） and catechol （CC） was developed using Au nanoparticles （AuNPs） fabricated on reduced graphene oxide/polyimide （PIIRGO） film by electroless deposition. The electrochemical behaviors of HQ and CC at PIIRGO-AuNPs electrode were investigated by cyclic voltammetry （CV） and differential pulse voltammetry （DPV）. Under the optimized condition, the current responses at PI/RGO-AuNPs electrode were linear over ranges from 1 to 654 mol/L for HQ and from 2 to 1289 mol/L for CC, with the detection limits of 0.09 and 0.2 mollL, respectively. The proposed electrode exhibited good reproducibility, stability and selectivity. In addition, the proposed electrode was successfully applied in the determination of HQ and CC in tap water and the Yellow River samples.

BRITTLE PLANT1 is required for normal cell wall composition and mechanical strength in rice

A series of nucleotide sugar interconversion enzymes(NSEs) generate the activated sugar donors required for biosynthesis of cell wall matrix polysaccharides and glycoproteins. UDPglucose 4-epimerases(UGEs) are NSEs that function in the interconversion of UDP-glucose(UDP-Glc) and UDP-galactose(UDP-Gal). The roles of UDP-glucose 4-epimerases in monocots remain unclear due to redundancy in the pathways. Here, we report a brittle plant(bp1) rice mutant that exhibits brittle leaves and culms at all growth stages. The mutant culms had reduced levels of rhamnogalacturonan I, homogalacturonan, and arabinogalactan proteins.Moreover, the mutant had altered contents of uronic acids, neutral noncellulosic monosaccharides, and cellulose. Map-based cloning demonstrated that OsBP1 encodes a UDPglucose 4-epimerase(OsUGE2), a cytosolic protein. We also show that BP1 can form homoand hetero-protein complexes with other UGE family members and with UDP-galactose transporters 2(OsUGT2) and 3(OsUGT3), which may facilitate the channeling of Gal to polysaccharides and proteoglycans. Our results demonstrate that BP1 participates in regulating the sugar composition and structure of rice cell walls.

Analyzing the risk of drug abuse for morphine-containing Chinese patent medicines in China

Chinese patent medicines（CPMs） are widely used across China, and they are differently administrated from chemical drugs. For traditional reasons, CPMs may contain opium-derived compounds, such as morphine, which may pose the issues of drug abuse and addiction. In the present study, we aimed to evaluate the present risk of morphine-containing CPMs in causing drug abuse and addiction, based on a questionnaire-based approach and from a medicinal administrative perspective. We chose 76 CPMs containing morphine from government document and set them as the study group, and 10 chemical drugs containing morphine were set as the control group. Because there is no ready-made method, we created an evaluation sheet consisting of five questions to evaluate each drug and generate a risk-value score. Crosstabs analysis using SPSS 15.0 was conducted to obtain the influencing factors. We found that the study group obtained a mean score of 2.04 for the risk value, which was five times of that of the control group. Specifically, no maximum limit of morphine or codeine was set in product quality standards for more than four-fifth of the drugs. Moreover, 46.0% of package inserts failed to show any warning about addiction or prohibition over the long-term use of the drugs. The number of ingredients, as well as the functions of the drugs, was found to correlate with the risk value. Our findings suggested that CPMs were more risky in causing drug abuse and addiction than chemical drugs. Approaches, such as i） controlling the number of ingredients, ii） setting up maximum limit of morphine or codeine in quality standard, iii） providing more information on the package insert of drugs and iv） monitoring the drug containing both morphine and ephedrine, will be effective in reducing the risk of drug abuse and addiction.