ABSTRACT
Aberrant alterations of rearranged during transfection (RET) have been identified as actionable drivers of multiple cancers, including thyroid carcinoma and lung cancer. Currently, several approved multikinase inhibitors such as vandetanib and cabozantinib demonstrate clinical activity in patients with RET-rearranged or RET-mutant cancers. However, the observed response rates are only modest and the 'off-target' toxicities resulted from the inhibition of other kinases is also a concern. Herein, we designed and synthesized a series of RET inhibitors based on the structure of selective RET inhibitor BLU-667 and investigated their biological activities. We identified compound 9 as a novel potent and selective RET inhibitor with improved drug-like properties. Compound 9 exhibits a selective inhibitory profile with an inhibitory concentration 50 (IC50) of 1.29 nM for RET and 1.97 (RET V804M) or 0.99 (RET M918T) for mutant RETs. The proliferation of Ba/F3 cells transformed with NSCLC related KIF5B-RET fusion was effectively suppressed by compound 9 (IC50 = 19 nM). Additionally, compound 9 displayed less 'off-target' effects than BLU-667. In mouse xenograft models, compound 9 repressed tumor growth driven by KIF5B-RET-Ba/F3 cells in a dose-dependent manner. Based on its exceptional kinase selectivity, good potency and high exposure in tumor tissues, compound 9 represents a promising lead for the discovery of RET directed therapeutic agents and the study of RET-driven tumor biology.
Subject(s)
Drug Discovery , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-ret/antagonists & inhibitors , Animals , Cell Line , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Mice , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins c-ret/metabolism , Structure-Activity RelationshipABSTRACT
A scalable enantioselective nickel-catalyzed electrochemical reductive homocoupling of aryl bromides has been developed, affording enantioenriched axially chiral biaryls in good yield under mild conditions using electricity as a reductant in an undivided cell. Common metal reductants such as Mn or Zn powder resulted in significantly lower yields in the absence of electric current under otherwise identical conditions, underscoring the enhanced reactivity provided by the combination of transition metal catalysis and electrochemistry.
ABSTRACT
BACKGROUND: Catechins, caffeine, and theanine as three important metabolites in the tea leaves play essential roles in the formation of specific taste and shows potential health benefits to humans. However, the knowledge on the dynamic changes of these metabolites content over seasons, as well as the candidate regulatory factors, remains largely undetermined. RESULTS: An integrated transcriptomic and metabolomic approach was used to analyze the dynamic changes of three mainly metabolites including catechins, caffeine, and theanine, and to explore the potential influencing factors associated with these dynamic changes over the course of seasons. We found that the catechins abundance was higher in Summer than that in Spring and Autumn, and the theanine abundance was significantly higher in Spring than that in Summer and Autumn, whereas caffeine exhibited no significant changes over three seasons. Transcriptomics analysis suggested that genes in photosynthesis pathway were significantly down-regulated which might in linkage to the formation of different phenotypes and metabolites content in the tea leaves of varied seasons. Fifty-six copies of nine genes in catechins biosynthesis, 30 copies of 10 genes in caffeine biosynthesis, and 12 copies of six genes in theanine biosynthesis were detected. The correlative analysis further presented that eight genes can be regulated by transcription factors, and highly correlated with the changes of metabolites abundance in tea-leaves. CONCLUSION: Sunshine intensity as a key factor can affect photosynthesis of tea plants, further affect the expression of major Transcription factors (TFs) and structural genes in, and finally resulted in the various amounts of catechins, caffeine and theaine in tea-leaves over three seasons. These findings provide new insights into abundance and influencing factors of metabolites of tea in different seasons, and further our understanding in the formation of flavor, nutrition and medicinal function.
Subject(s)
Caffeine/biosynthesis , Camellia sinensis/metabolism , Catechin/biosynthesis , Glutamates/biosynthesis , Gene Expression , Metabolomics , Phenotype , Plant Leaves/metabolism , Seasons , Transcription Factors/metabolism , TranscriptomeABSTRACT
Telework has been promoted for decades as one of the traffic demand management policies to alleviate congestion during peak periods and reduce work-related trips, along with other benefits. However, less clear is the role played by life stages (i.e., gender, marital status and parenthood) on telework behavior. This study investigated to which extent telework frequency associated with life stages, and how these associations could be explained based on the work-life conflict perspective. Representative data were obtained from German Microcensus 2010 (N = 188,081 participants). The outcome variable was measured as ordered telework participation levels (i.e., never, infrequently and frequently). After testing for multicollinearity, a zero-inflated ordered probit regression model was applied to assess the associations between telework and family-life stages, while adjusting for individual, household, job-related and environmental characteristics. Results suggest that life stages associate with telework behavior in a complex way. Three patterns have been distinguished. Specifically, irrespective of gender and marital status, parents are less likely to telework compared to those without children. Regarding individuals without children, single individuals are more likely to telework than married ones, and males more likely than females. In contrast, for individuals with children, the partnered parents are more likely to telework than single parents, and females more likely than males. Our findings suggest that as the most important feature in family-life stages, children play a vital role in telework behavior. It not only increases both work-to-family conflict and family-to-work conflict, but also triggers housework re-division within couples and aggravates gender differences. Policies that support formal childcare resources could relieve the family-to-work conflict and encourage people to work at home.
ABSTRACT
We have developed a Ni-catalyzed enantioselective hydroarylation of styrenes with arylboronic acids using MeOH as the hydrogen source, providing an efficient method to access 1,1-diarylalkanes, which are essential structural units in many biologically active compounds. In addition, Ni-catalyzed enantioselective hydrovinylation of styrenes with vinylboronic acids is also realized with good yields and enantioselectivities. The synthetic utility was demonstrated by the efficient synthesis of ( R)-(-)-ibuprofen.
ABSTRACT
BACKGROUND: Metastasis of prostate cancer (PCa) is largely affected by natural killer (NK) cells. This study aimed to clarify the mechanisms underlying tumor cells escaping from NK cells mediated by HIF-1α. METHODS: MiR-224 expression in lymphocytes and HIF-1α protein level in NK cells were determined by qRT-PCR and western blot, respectively. The amount of NKp46+ NK cells was detected with flow cytometry. The IFN-γ level was examined by enzyme linked immunosorbent assay (ELISA). NK cells were tested for cytolytic activity with a Non-Radioactive Cytotoxicity Assay, and treated with oxygenglucose deprivation (OGD) for hypoxia simulation. Interaction between miR-224 and NCR1 was evaluated with dual luciferase reporter assay. RESULTS: MiR-224 was down-regulated in lymphocytes isolated from prostate cancer tissues (nâ¯=â¯10). Overexpression of miR-224 protected prostate cancer from NK cells. HIF-1α increased miR-224 to inhibit the killing capability of NK cells on prostate cancer. MiR-224 controlled the expression of NCR1. Overexpression of miR-224 protected prostate cancer from NK cells through NCR1/NKp46 signaling. Suppression of HIF-1α enhanced the cytotoxicity of NK cells on prostate cancer via miR-224/NCR1 pathway. CONCLUSION: HIF-1α inhibits NCR1/NKp46 pathway through up-regulating miR-224, which affects the killing capability of NK cells on prostate cancer, thus inducing immune escape of tumor cells.
Subject(s)
Hypoxia-Inducible Factor 1, alpha Subunit/immunology , MicroRNAs/metabolism , Natural Cytotoxicity Triggering Receptor 1/metabolism , Prostatic Neoplasms/immunology , Prostatic Neoplasms/metabolism , Tumor Escape/immunology , Cell Line , Cytotoxicity, Immunologic , Down-Regulation , Humans , In Vitro Techniques , Killer Cells, Natural/immunology , Killer Cells, Natural/metabolism , Lymphocytes/immunology , Lymphocytes/metabolism , Male , MicroRNAs/genetics , Prostatic Neoplasms/genetics , Signal Transduction , Tumor Escape/genetics , Up-RegulationABSTRACT
Treatment of Syrian hamsters on the day of birth with the prototypical endocrine disruptor and synthetic estrogen, diethylstilbestrol (DES), leads to 100% occurrence of uterine hyperplasia/dysplasia in adulthood, a large proportion of which progress to neoplasia (endometrial adenocarcinoma). Consistent with our prior gene expression analyses at the mRNA and protein levels, we now report (based on microarray, real-time polymerase chain reaction, and in situ hybridization analyses) that progression of the neonatal DES-induced dysplasia/neoplasia phenomenon in the hamster uterus also includes a spectrum of microRNA expression alterations (at both the whole-organ and cell-specific level) that differ during the initiation (upregulated miR-21, 200a, 200b, 200c, 29a, 29b, 429, 141; downregulated miR-181a) and promotion (downregulated miR-133a) stages of the phenomenon. The biological processes targeted by those differentially expressed miRNAs include pathways in cancer and adherens junction, plus regulation of the cell cycle, apoptosis, and miRNA functions, all of which are consistent with our model system phenotype. These findings underscore the need for continued efforts to identify and assess both the classical genetic and the more recently recognized epigenetic mechanisms that truly drive this and other endocrine disruption phenomena.
Subject(s)
Diethylstilbestrol/toxicity , MicroRNAs/biosynthesis , Uterine Cervical Dysplasia/chemically induced , Uterine Cervical Dysplasia/genetics , Animals , Animals, Newborn , Apoptosis/drug effects , Cricetinae , Endocrine Disruptors/toxicity , Female , Gene Expression Profiling/methods , Mesocricetus , MicroRNAs/genetics , MicroRNAs/metabolism , Uterine Cervical Dysplasia/pathology , Uterine Neoplasms/chemically induced , Uterine Neoplasms/genetics , Uterine Neoplasms/pathology , Uterus/drug effects , Uterus/metabolism , Uterus/pathologyABSTRACT
OBJECTIVE: Hyaluronic acid is one of the best materials of water retention which can be used in vaginal atrophy. This study is to evaluate the role and mechanism of the hyaluronic acid vaginal gel (Hyalofemme) in the vaginal epithelium of ovariectomized rats. MATERIALS AND METHODS: Sixty SD rats were randomly divided into control group (Sham ovariectomy, Sham-OVX), tendency group (ovariectomy, OVX), and experiment group (ovariectomy+Hyalofemme, OVX+Hyalofemme). The hyaluronic acid vaginal gel was administered local vaginal therapy to the experiment group with cytologicaly confirmed vaginal atrophy. The doses were adjusted by animal weight according to human dosage. After daily treatment for 14 days, VEGF and P-AKT activations were detected by Western blot in the experiment group. RESULTS: The hyaluronic acid vaginal gel proved to be very effective in the cytological reversal of vaginal atrophy but did not increase uterine weight. Vaginal microecosystem indicators were negative in the control group and the experiment group. By contrast, the indicators were positive in the tendency group. CONCLUSION: Hyaluronic acid vaginal gel is effective in the reversal of vaginal atrophy and is beneficial for improving vaginal microecosystem in the postmenopausal rat model. The hyaluronic acid vaginal gel can also improve the repair capacity of the vaginal epithelium.
Subject(s)
Epithelium/drug effects , Hyaluronic Acid/pharmacology , Vagina/drug effects , Vaginal Diseases/drug therapy , Administration, Intravaginal , Animals , Atrophy/drug therapy , Atrophy/pathology , Disease Models, Animal , Epithelium/pathology , Female , Hyaluronic Acid/therapeutic use , Rats , Rats, Sprague-Dawley , Vagina/pathology , Vaginal Creams, Foams, and Jellies/pharmacology , Vaginal Creams, Foams, and Jellies/therapeutic use , Vaginal Diseases/pathologyABSTRACT
BACKGROUND: Heart failure is a major public health problem worldwide. Shengmai, a traditional Chinese herbal medicine, has long been used as a complementary treatment for heart failure in China. This is an update of a Cochrane Review published in 2012. OBJECTIVES: To determine the effect (both benefits and harms) of Shengmai in treatment of people with heart failure. SEARCH METHODS: We searched CENTRAL on The Cochrane Library (Issue 5 of 12, April 2013); DARE on The Cochrane Library (Issue 2 of 4, April 2013); MEDLINE (1948 to June Week 1 2013); EMBASE (1980 to 2013 Week 23); AMED (1985 to August 2008); BIOSIS (1969 to 7 June 2013); CBM (1978 to June 2013); VIP (1989 to June 2013); and CNKI (1979 to June 2013). We also handsearched Chinese journals and did not apply any language restrictions. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of Shengmai plus usual treatment for heart failure versus usual treatment alone, or Shengmai versus placebo, irrespective of blinding status. In this update we only included studies with a clear description of randomisation methods and classified as true RCTs. DATA COLLECTION AND ANALYSIS: Two authors independently selected trials, assessed methodological quality and extracted data. We calculated dichotomous data as risk ratios (RRs) and continuous data as mean differences (MDs) or standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs). We used a fixed-effect model to perform meta-analysis for outcomes without heterogeneity; and a random-effects model to perform meta-analysis for outcomes with heterogeneity. MAIN RESULTS: We included a total of 14 RCTs (858 patients) in this review update, four of which were new trials. Of these 14 RCTs, 11 trials compared Shengmai plus usual treatment with usual treatment alone, and three trials compared Shengmai with placebo. Improvement of NYHA functional classification was more common in patients taking Shengmai plus usual treatment than in those receiving usual treatment alone (RR 0.37; 95% CI 0.26 to 0.51; 10 trials, 672 participants; low quality evidence). Beneficial effects of Shengmai in treating heart failure were also observed in other outcomes, including exercise test, ejection fraction and cardiac output. The three RCTs (106 patients) comparing Shengmai with placebo reported improvement in NYHA functional classification and in stroke volume. Three of the 14 RCTs reported a total of six patients with mild adverse effects and two were withdrawn due to the adverse effects. The adverse events rate was 1.21%. AUTHORS' CONCLUSIONS: Shengmai may exert a positive effect on heart failure, especially for improving NYHA functional classification when Shengmai plus usual treatment is used. The review results should be interpreted with caution due to the high risk of bias of the included studies (particularly regarding allocation concealment and blinding), the small sample size of these studies, and the significant heterogeneity in outcomes such as ejection function, cardiac output and stroke volume. There was no evidence available concerning the effect of Shengmai on mortality, and more high quality studies with long-term follow-up are warranted.
Subject(s)
Cardiotonic Agents/therapeutic use , Drugs, Chinese Herbal/therapeutic use , Heart Failure/drug therapy , Phytotherapy/methods , Drug Combinations , Humans , Randomized Controlled Trials as Topic , Treatment OutcomeABSTRACT
Drawing on the core idea of Propensity Score Matching, this study proposes a new concept named Historical Traffic Violation Propensity to describe the driver's historical traffic violations, and combines the new concept with an improved mutual information-based feature selection algorithm to construct a method for screening key traffic violations from the perspective of expressing driver's accident risk. The validation analysis based on the real data collected in Shenzhen demonstrated that drivers' state of Historical Traffic Violation Propensity on 19 key traffic violations screened have a stronger predictive ability of their subsequent accidents compared to the level in existing research. The positive state of Historical Traffic Violation Propensity on 'Drinking', 'Parking in dangerous areas', 'Wrong use of turn lights', 'Violating prohibited and restricted traffic regulations', and 'Disobeying prohibition sign' will increase the probability of a driver's subsequent accident by more than 1.7 times. The research provides directions to more efficiently and accurately capture the driver's accident risk through historical traffic violations, which is valuable for identifying high-risk drivers as well as the key psychological or physical risk factors that manifest in daily driving activities and lead to subsequent accidents.
Subject(s)
Automobile Driving , Humans , Accidents, Traffic/prevention & control , Risk Factors , Dangerous BehaviorABSTRACT
Accurately and quickly mining the hidden information in railway dangerous goods transportation (RDGT) accident reports has great significance for its safety management. In this paper, a data mining method Logistics-DT-TFP is proposed for analysing the causes of RDGT accidents. Firstly, analyse the transportation process, extract the cause of the accident, and classify the severity of the accident. Then, using ordered multi-classification Logistic regression for correlation calculation, qualitatively judge and quantitatively analyse the relationship between each cause and the severity of the accident. The feature tags of the Decision Tree (DT) are screened, the C5.0 algorithm is used to obtain the accident coupling rules. Next, the FP-Growth algorithm is used to mine frequent itemsets, and TOP-K is used to improve it and output effective association rules with the degree of lift as the indicator, which avoids repeated traversal of the database, shortens the time complexity, and reduces the impact of the minimum support setting on the calculation results. The degree of lift among the causes in the coupling chain is calculated as a complement to the extraction of coupling rules. Finally, based on the analysis and mining results of case study, the management strategies for railway dangerous goods are proposed.
Subject(s)
Accidents, Traffic , Transportation , Humans , Causality , Data Mining/methods , AlgorithmsABSTRACT
This article reviews the research progress of rehabilitation treatment and nursing care of patients with neurogenic bladder after spinal cord injury, in order to provide reference for the rehabilitation treatment and nursing care of patients. We reviewed recent medical literature on patients with neurogenic bladder, focusing on neurogenic bladder caused by spinal cord injury. We analyzed 30 recent of publications in patients with neurogenic bladder after spinal cord injury, in addition to reviewing and evaluating the commonly used rehabilitation nursing methods for neurogenic bladder. Psychological counseling is a vital aspect which cannot be neglected in the process of neurogenic bladder rehabilitation. Hitherto, the commonly used drug and surgical treatments may have negatively impacted the mental health of patients in varying degrees. However, in clinical practice, applying intermittent catheterization in patients who have neurogenic bladder with spinal cord injury may help improve patients' life quality, mitigate psychological burden, and reduce negative emotions.
ABSTRACT
Antibiotics have been widely used for improving human and animal health and well-being for many decades. However, the enormous antibiotic usage in agriculture especially for livestock leads to considerable quantities of antibiotic residues in associated food products and can reach potentially hazardous levels for consumers. Therefore, timely detection and systematical surveillance on residual antibiotics in food materials are of significance to minimize the negative impact caused by such unwanted antibiotic leftovers. To this end, we constructed a cloud-platform-based system (ARSCP) for comprehensive surveillance of antibiotic residues in food materials. With the system, we collected 126,560 samples from 68 chicken farms across China and detected the antibiotic residues using a rapid detection colorimetric commercial (Explorer 2.0) kit and UPLC-MS/MS. Only 108 (0.085 %) of the samples contained residual antibiotics exceeding the MRLs and all data were subjected to ARSCP system to provide a landscape of antibiotic residues in China. As a proof-of-concept, we provided an overview of residual antibiotics based on data from China, but the system is generally applicable to track and monitor the antibiotic residues globally when the data from other countries are incorporated. We used the combined Explorer 2.0 and MS data to construct ARSCP, an antimicrobial residue surveillance cloud platform for raw chicken samples. ARSCP can be used for rapid detection and real-time monitoring of antibiotic residues in animal food and provides both data management and risk warning functions. This system provides a solution to improve the management of facilities that must monitor antibiotic MRLs in food animal products that can reduce the pollution of antibiotics to the environment.
Subject(s)
Anti-Infective Agents , Cloud Computing , Animals , Humans , Chromatography, Liquid , Tandem Mass Spectrometry , Anti-Bacterial Agents , Animal Feed , Disease ProgressionABSTRACT
The extensive use of tetracycline antibiotics has led to the widespread presence of tetracycline-resistance genes in Gram-negative bacteria and this poses serious threats to human and animal health. In our previous study, we reported a method for rapid detection of Tet(X)-producers using MALDI-TOF MS. However, there have been multiple machineries involved in tetracycline resistance including efflux pump, and ribosomal protection protein. Our previous demonstrated the limitation in probing the non-Tet(X)-producing tetracycline-resistant strains. In this regard, we further developed a MALDI-TOF MS method to detect and differentiate Tet(X)-producers and non-Tet(X)-producing tetracycline-resistant strains. Test strains were incubated with tigecycline and oxytetracycline in separate tubes for 3 h and then analyzed spectral peaks of tigecycline, oxytetracycline, and their metabolite. Strains were distinguished using MS ratio for [metabolite/(metabolite+ tigecycline or oxytetracycline)]. Four control strains and 319 test strains were analyzed and the sensitivity was 98.90% and specificity was 98.34%. This was consistent with the results obtained from LC-MS/MS analysis. Interestingly, we also found that the reactive oxygen species (ROS) produced by tetracycline-susceptible strains were able to promote the degradation of oxytetracycline. Overall, the MALDITet(X)-plus test represents a rapid and reliable method to detect Tet(X)-producers, non-Tet(X)-producing tetracycline-resistant strains, and tetracycline-susceptible strains.
Subject(s)
Oxytetracycline , Tetracycline , Animals , Anti-Bacterial Agents/pharmacology , Chromatography, Liquid , Gram-Negative Bacteria/genetics , Microbial Sensitivity Tests , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Tandem Mass Spectrometry , Tetracycline/pharmacology , Tigecycline/pharmacologyABSTRACT
Currently, the road safety performance of a national- or province-level is absorbing much attention from practitioners and academics. A variety of models based on Data Envelopment Analysis (DEA) have been presented to appraise road safety performance in previous literature. However, the main weakness of these methods is that the decision-maker's psychological behavior is neglected. Besides, Cross Efficiency Method (CEM) adopts the weighted average to aggregate the cross efficiencies which may lead to information loss. To address these limitations, a hybrid road safety evaluation model was constructed by integrating CEM, regret theory, and Weighted Aggregated Sum Product Assessment (WASPAS) to appraise the road safety performance of Chinese provinces. In the presented model, regret theory is employed to depict the psychological behavior of the decision-maker. Then entropy weight method is utilized to calculate the weight of self-evaluation and peer-evaluation. To reduce information loss, WASPAS is adopted to fuse the cross efficiencies and derive the ranking of decision-making units. Finally, the presented model is employed to assess the road safety efficiency in the province of mainland China. The results show that the mean of road safety efficiency score for the eastern, central, and western areas is gradually decreasing. Furthermore, the outcomes of a comparative analysis represent that the results obtained by the proposed model outperform the CEM and DEA road safety model.
Subject(s)
Accidents, Traffic , Emotions , Accidents, Traffic/prevention & control , China , HumansABSTRACT
Essential decision-making tasks such as power management in future vehicles will benefit from the development of artificial intelligence technology for safe and energy-efficient operations. To develop the technique of using neural network and deep learning in energy management of the plug-in hybrid vehicle and evaluate its advantage, this article proposes a new adaptive learning network that incorporates a deep deterministic policy gradient (DDPG) network with an adaptive neuro-fuzzy inference system (ANFIS) network. First, the ANFIS network is built using a new global K-fold fuzzy learning (GKFL) method for real-time implementation of the offline dynamic programming result. Then, the DDPG network is developed to regulate the input of the ANFIS network with the real-world reinforcement signal. The ANFIS and DDPG networks are integrated to maximize the control utility (CU), which is a function of the vehicle's energy efficiency and the battery state-of-charge. Experimental studies are conducted to testify the performance and robustness of the DDPG-ANFIS network. It has shown that the studied vehicle with the DDPG-ANFIS network achieves 8% higher CU than using the MATLAB ANFIS toolbox on the studied vehicle. In five simulated real-world driving conditions, the DDPG-ANFIS network increased the maximum mean CU value by 138% over the ANFIS-only network and 5% over the DDPG-only network.
ABSTRACT
Antimicrobial resistance is recognized as one of the major global health challenges of the 21st century. Synergistic combinations for antimicrobial therapies can be a good strategy for the treatment of multidrug resistant infections. We examined the ability of a group of 29 plant essential oils as substances which enhance the antibiotic activity. We used a modified well diffusion method to establish a high-throughput screening method for easy and rapid identification of high-level enhancement combinations against bacteria. We found that 25 essential oils possessed antibacterial activity against Escherichia Coli ATCC 25922 and methicillin-resistant Staphylococcus aureus (MRSA) 43300 with MICs that ranged from 0.01% to 2.5% v/v. We examined 319 (11 × 29) combinations in a checkerboard assay with E. Coli ATCC 25922 and MRSA 43300, and the result showed that high-level enhancement combinations were 48 and 44, low-level enhancement combinations were 214 and 211, and no effects combinations were 57 and 64, respectively. For further verification we randomly chose six combinations that included orange and Petitgrain essential oils in a standard time-killing assay. The results are in great agreement with those of the well diffusion assays. Therefore, the modified diffusion method was a rapid and effective method to screen high-level enhancement combinations of antibiotics and essential oils.
ABSTRACT
Functional analyses of the Arabidopsis genome require analysis of the gametophytic generation, since approximately 10% of the genes are expressed in the male gametophyte and approximately 9% in the female gametophyte. Here we describe the genetic and molecular characterization of 67 Ds insertion lines that show reduced transmission through the male gametophyte. About half of these mutations are male gametophytic-specific mutations, while the others also affect female transmission. Genomic sequences flanking both sides of the Ds element were recovered for 39 lines; for 16 the Ds elements were inserted in or close to coding regions, while 7 were located in intergenic/unannotated regions of the genome. For the remaining 16 lines, chromosomal rearrangements such as translocations or deletions, ranging between 30 and 500 kb, were associated with the transposition event. The mutants were classified into five groups according to the developmental processes affected; these ranged from defects in early stages of gametogenesis to later defects affecting pollen germination, pollen tube growth, polarity or guidance, or pollen tube-embryo sac interactions or fertilization. The isolated mutants carry Ds insertions in genes with diverse biological functions and potentially specify new functions for several unannotated or unknown proteins.
Subject(s)
Arabidopsis/genetics , Gametogenesis/genetics , Genes, Plant , Germ Cells/physiology , Mutagenesis, Insertional , Arabidopsis/physiology , Arabidopsis Proteins/genetics , Arabidopsis Proteins/physiology , DNA Mutational Analysis , Fertilization/genetics , Germ Cells/metabolism , Phenotype , Plant Proteins/genetics , Plant Proteins/physiology , Plants, Genetically Modified , Pollen/genetics , Pollen/growth & development , Pollen Tube/genetics , Pollen Tube/growth & development , Sex Characteristics , Transcription Factors/genetics , Transcription Factors/physiologyABSTRACT
Macrophomina phaseolina, causative agent of the charcoal rot disease, impacts over 500 plant species, causing devastating crop failures worldwide. Due to the lack of effective management approach, charcoal rot can result in serious loss, especially during years with hot and dry summers. This study aims to evaluate the effectiveness of using the RNA interference (RNAi) mechanism to suppress the growth of M. phaseolina, through exogenous application of small interfering RNA (siRNA) targeting one of the chitin synthase (MpCHS) genes in the M. phaseolina genome. Since chitin is one of the main components in the fungal cell wall, we hypothesize that suppressing the expression of MpCHS through RNAi will negatively affect the growth of the fungus, which may result in reduced virulence toward the host. Of the seven candidate MpCHS genes assessed, MpCHS6 showed consistent expression in plate-grown fungus and in infected plant tissue and was chosen as the target for RNAi knockdown. Two siRNAs were designed to target MpCHS6 and tested through in vitro application in M. phaseolina culture. Both siRNAs suppressed growth of the fungus at multiple time points and under varied environmental conditions. More importantly, the growth suppression was well correlated with down-regulation of the MpCHS6 gene. These results indicate that exogenous siRNAs can suppress gene expression in M. phaseolina even when applied in vitro. In addition, targeting a MpCHS gene may provide an effective way to control the fungal growth. Our study provides firsthand knowledge on RNAi in M. phaseolina, which benefits not only basic research that focuses on understanding gene function in this species but also application of RNAi-based technology in disease control in the future.
Subject(s)
Ascomycota/growth & development , Chitin Synthase/genetics , RNA, Small Interfering/genetics , Ascomycota/genetics , Ascomycota/metabolism , Gene Expression Regulation, Fungal , Genes, Fungal , Melanins/metabolism , Mycelium/growth & development , Mycelium/metabolism , Plant Diseases/microbiology , RNA InterferenceABSTRACT
Understanding the soil respiration characteristics in response to nitrogen and phosphorus addition in farming-withdrawn grasslands within semi-arid loess hilly-gully regions is of great importance for providing a theoretical basis for evaluating the effects of artificial regulation approaches on carbon cycling. We report on a field experiment that was undertaken from May to September 2018 in a farming-withdrawn grassland ecosystem in China, which is dominated by Stipa bungeana and Lespedeza davurica. Three different levels of nitrogen and phosphorus additions were used, including three main plots of N[0, 50, and 100 kg·(hm2·a)-1] and three subplots of P (P2O5)[0,40, and 80 kg·(hm2·a)-1]. The soil respiration rate, heterotrophic respiration rate, soil temperature, and soil moisture were measured monthly in each treatment. Results showed that N and P addition had no effect on soil temperature or moisture content (P>0.05). The soil respiration rate showed an obvious monthly variation and peaked in July. In the treatment without fertilizer addition, the monthly mean soil respiration rate, heterotrophic respiration rate, and autotrophic respiration rate were 0.69, 0.39, and 0.29 g·(m2·h)-1, respectively. P addition had no significant effect on the soil respiration rate and its components without N addition (P>0.05). Under conditions of N addition, P addition significantly increased the soil respiration rate and its component (P<0.05). The monthly mean soil respiration rate, heterotrophic respiration rate, and autotrophic respiration rate were 0.93, 0.50, and 0.47 g·(m2·h)-1, respectively. The Q10 (i.e., temperature sensitivity) values for soil respiration, heterotrophic respiration, and autotrophic respiration in unfertilized soil were 1.86, 2.36, and 2.24, respectively. The addition of N and P reduced the Q10 value of soil respiration and its components. Our findings suggest that the response of soil respiration and its two components to N and P addition in studied farming-withdrawn grassland in the semiarid loess hilly-gully region were closely related to their addition amounts.