239 results on '"Zhihui, Cheng"'
Search Results
2. Regulatory and structural mechanisms of PvrA-mediated regulation of the PQS quorum-sensing system and PHA biosynthesis in Pseudomonas aeruginosa
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Xiaolei Pan, Han Liang, Xinrui Zhao, Qionglin Zhang, Lei Chen, Zhuo Yue, Liwen Yin, Yongxin Jin, Fang Bai, Zhihui Cheng, Mark Bartlam, and Weihui Wu
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Genetics - Abstract
Pseudomonas aeruginosa is capable of causing acute and chronic infections in various host tissues, which depends on its abilities to effectively utilize host-derived nutrients and produce protein virulence factors and toxic compounds. However, the regulatory mechanisms that direct metabolic intermediates towards production of toxic compounds are poorly understood. We previously identified a regulatory protein PvrA that controls genes involved in fatty acid catabolism by binding to palmitoyl-coenzyme A (CoA). In this study, transcriptomic analyses revealed that PvrA activates the Pseudomonas quinolone signal (PQS) synthesis genes, while suppressing genes for production of polyhydroxyalkanoates (PHAs). When palmitic acid was the sole carbon source, mutation of pvrA reduced production of pyocyanin and rhamnolipids due to defective PQS synthesis, but increased PHA production. We further solved the co-crystal structure of PvrA with palmitoyl-CoA and identified palmitoyl-CoA-binding residues. By using pvrA mutants, we verified the roles of the key palmitoyl-CoA-binding residues in gene regulation in response to palmitic acid. Since the PQS signal molecules, rhamnolipids and PHA synthesis pathways are interconnected by common metabolic intermediates, our results revealed a regulatory mechanism that directs carbon flux from carbon/energy storage to virulence factor production, which might be crucial for the pathogenesis.
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- 2023
3. SSR markers development and their application in genetic diversity evaluation of garlic (Allium sativum) germplasm
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Birong Chen, Lijun Qiao, Siyu Zhang, Yujie Zheng, Chengchen Zhi, Xiaxia Li, Zhihui Cheng, and Yupeng Pan
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Genetics ,Germplasm ,Genetic diversity ,Genetic distance ,Genetic marker ,Genetic variation ,food and beverages ,Mantel test ,Plant Science ,Phenotypic trait ,Biology ,Allium sativum ,Ecology, Evolution, Behavior and Systematics - Abstract
Garlic (Allium sativum L.), an asexually propagated vegetable and medicinal crop, has abundant genetic variation. Genetic diversity evaluation based on molecular markers has apparent advantages since their genomic abundance, environment insensitivity, and non-tissue specific features. However, the limited number of available DNA markers, especially SSR markers, are insufficient to conduct related genetic diversity assessment studies in garlic. In this study, 4372 EST-SSR markers were newly developed, and 12 polymorphic markers together with other 17 garlic SSR markers were used to assess the genetic diversity and population structure of 127 garlic accessions. The averaged polymorphism information content (PIC) of these 29 SSR markers was 0.36, ranging from 0.22 to 0.49. Seventy-nine polymorphic loci were detected among these accessions, with an average of 3.48 polymorphic loci per SSR. Both the clustering analyses based on either the genotype data of SSR markers or the phenotypic data of morphological traits obtained genetic distance divided the 127 garlic accessions into three clusters. Moreover, the Mantel test showed that genetic distance had no significant correlations with geographic distance, and weak correlations were found between genetic distance and the phenotypic traits. AMOVA analysis showed that the main genetic variation of this garlic germplasm collection existed in the within-population or cluster. Results of this study will be of great value for the genetic/breeding studies in garlic and enhance the utilization of these garlic germplasms.
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- 2022
4. Diversified crop rotation improves continuous monocropping eggplant production by altering the soil microbial community and biochemical properties
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Muhammad Imran Ghani, Ahmad Ali, Muhammad Jawaad Atif, Shamina Imran Pathan, Giacomo Pietramellara, Muhammad Ali, Bakht Amin, and Zhihui Cheng
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Soil Science ,Plant Science - Published
- 2022
5. Distinct Contact Scaling Effects in MoS2 Transistors Revealed with Asymmetrical Contact Measurements
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Zhihui Cheng, Jonathan Backman, Huairuo Zhang, Hattan Abuzaid, Guoqing Li, Yifei Yu, Linyou Cao, Albert V. Davydov, Mathieu Luisier, Curt A. Richter, and Aaron D. Franklin
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contact scaling ,current crowding ,negative differential resistance ,transfer length ,two-dimensional field-effect transistors ,Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Abstract
2D semiconducting materials have immense potential for future electronics due to their atomically thin nature, which enables better scalability. While the channel scalability of 2D materials has been extensively studied, the current understanding of contact scaling in 2D devices is inconsistent and oversimplified. Here physically scaled contacts and asymmetrical contact measurements (ACMs) are combined to investigate the contact scaling behavior in 2D field-effect transistors. The ACMs directly compare electron injection at different contact lengths while using the exact same MoS2 channel, eliminating channel-to-channel variations. The results show that scaled source contacts can limit the drain current, whereas scaled drain contacts do not. Compared to devices with long contact lengths, devices with short contact lengths (scaled contacts) exhibit larger variations, 15% lower drain currents at high drain-source voltages, and a higher chance of early saturation and negative differential resistance. Quantum transport simulations reveal that the transfer length of Ni-MoS2 contacts can be as short as 5 nm. Furthermore, it is clearly identified that the actual transfer length depends on the quality of the metal-2D interface. The ACMs demonstrated here will enable further understanding of contact scaling behavior at various interfaces. ISSN:0935-9648 ISSN:1521-4095
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- 2023
6. PitA Controls the H2- and H3-T6SSs through PhoB in Pseudomonas aeruginosa
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Xinrui Zhao, Congjuan Xu, Junze Qu, Yongxin Jin, Fang Bai, Zhihui Cheng, Weihui Wu, and Xiaolei Pan
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Ecology ,Applied Microbiology and Biotechnology ,Food Science ,Biotechnology - Abstract
Pseudomonas aeruginosa is an opportunistic pathogenic bacterium that causes acute and chronic infections in humans. The type VI secretion systems (T6SSs) have been shown to associate with chronic infections.
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- 2023
7. How to report and benchmark emerging field-effect transistors
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Zhihui Cheng, Chin-Sheng Pang, Peiqi Wang, Son T. Le, Yanqing Wu, Davood Shahrjerdi, Iuliana Radu, Max C. Lemme, Lian-Mao Peng, Xiangfeng Duan, Zhihong Chen, Joerg Appenzeller, Steven J. Koester, Eric Pop, Aaron D. Franklin, and Curt A. Richter
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Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics ,ddc:621.3 ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Electrical and Electronic Engineering ,Instrumentation ,Electronic, Optical and Magnetic Materials - Abstract
Emerging low-dimensional nanomaterials have been studied for decades in device applications as field-effect transistors (FETs). However, properly reporting and comparing device performance has been challenging due to the involvement and interlinking of multiple device parameters. More importantly, the interdisciplinarity of this research community results in a lack of consistent reporting and benchmarking guidelines. Here we report a consensus among the authors regarding guidelines for reporting and benchmarking important FET parameters and performance metrics. We provide an example of this reporting and benchmarking process for a two-dimensional (2D) semiconductor FET. Our consensus will help promote an improved approach for assessing device performance in emerging FETs, thus aiding the field to progress more consistently and meaningfully., 15 pages, 3 figures
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- 2022
8. Uncertainty health risk assessment and regional control of drinking water: a case study of Hanyuan County, southwest mountainous area, China
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Zhengjiang Lin, Ying Liu, Zhihui Cheng, Rui Zhao, and Han Zhang
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Adult ,Chromium ,China ,Drinking Water ,Health, Toxicology and Mutagenesis ,Uncertainty ,Mercury ,General Medicine ,Risk Assessment ,Pollution ,Trace Elements ,Lead ,Metals, Heavy ,Carcinogens ,Humans ,Environmental Chemistry ,Child ,Water Pollutants, Chemical ,Cadmium ,Environmental Monitoring - Abstract
To evaluate the health risks of drinking water in Hanyuan County, 96 samples of peripheral drinking water were collected from 30 sites in the area. The samples were then analysed for physicochemical properties including Fe, Mn, NH 3 -N, , F-, Pb, Hg, As, Cr 6+ , Cd, and so on. The health risks of ten trace elements in drinking water were probabilistically assessed using the health risk assessment model and Monte Carlo simulation. On this basis, sequential indicator simulations were used to classify the health risk levels of drinking water in the region, to conduct hierarchical management and control. The results showed that except for , all other indicators met World Health Organisation standards and China’s drinking water sanitation standards. Drinking water presents a specific carcinogenic risk to adults, and the cumulative contribution of As and Cr 6+ exceeds 95%, and has a specific non-carcinogenic risk to children if the cumulative contribution of F - , , and As exceeds 90%. Grade I, II, and III non-carcinogenic risk areas accounted for 0.89%, 24.72%, and 74.39% of the total area of Hanyuan County, respectively, while grade I, II, and III carcinogenic risk areas accounted for 27.71%, 45.56%, and 26.73% of the total Hanyuan County area, respectively. Finally, according to the health risk characteristics of each control area, corresponding zoning control suggestions were proposed.
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- 2022
9. HMGN1 enhances CRISPR-directed dual-function A-to-G and C-to-G base editing
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Chao Yang, Zhenzhen Ma, Keshan Wang, Xingxiao Dong, Meiyu Huang, Yaqiu Li, Xiagu Zhu, Ju Li, Zhihui Cheng, Changhao Bi, and Xueli Zhang
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Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
C-to-G base editors have been successfully constructed recently, but limited work has been done on concurrent C-to-G and A-to-G base editing. In addition, there is also limited data on how chromatin-associated factors affect the base editing. Here, we test a series of chromatin-associated factors, and chromosomal protein HMGN1 was found to enhance the efficiency of both C-to-G and A-to-G base editing. By fusing HMGN1, GBE and ABE to Cas9, we develop a CRISPR-based dual-function A-to-G and C-to-G base editor (GGBE) which is capable of converting simultaneous A and C to G conversion with substantial editing efficiency. Accordingly, the HMGN1 role shown in this work and the resulting GGBE tool further broaden the genome manipulation capacity of CRISPR-directed base editors.
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- 2023
10. Different leafy vegetable cropping systems regulate growth, photosynthesis, and PSII functioning in mono-cropped eggplant by altering chemical properties and upregulating the antioxidant system
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Muhammad Imran Ghani, Ahmad Ali, Muhammad Jawaad Atif, Muhammad Ali, Mohammad Abass Ahanger, Xiaoyulong Chen, and Zhihui Cheng
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Plant Science - Abstract
Continuous cropping of eggplant threatened regional ecological sustainability by facilitating replanting problems under mono-cropping conditions. Therefore, alternative agronomic and management practices are required to improve crop productivity at low environmental cost for the development of sustainable agricultural systems in different regions. This study examined changes in soil chemical properties, eggplant photosynthesis, and antioxidant functioning in five different vegetable cropping systems over a 2-year period., 2017 and 2018. The results showed that welsh onion-eggplant (WOE), celery-eggplant (CE), non-heading Chinese cabbage-eggplant (NCCE), and leafy lettuce-eggplant (LLE) rotation systems significantly impacted growth, biomass accumulation, and yield than fallow-eggplant (FE). In addition, various leafy vegetable cropping systems, WOE, CE, NCCE, and LLT induced significant increases in soil organic matter (SOM), available nutrients (N, P, and K), and eggplant growth by affecting the photosynthesis and related gas exchange parameters with much evident effect due to CE and NCCE. Moreover, eggplant raised with different leafy vegetable rotation systems showed higher activity of antioxidant enzymes, resulting in lower accumulation of hydrogen peroxide and hence reduced oxidative damage to membranes. In addition, fresh and dry plant biomass was significantly increased due to crop rotation with leafy vegetables. Therefore, we concluded that leafy vegetable crop rotation is a beneficial management practice to improve the growth and yield of eggplant.
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- 2023
11. MvfR Controls Tolerance to Polymyxin B by Regulating rfaD in Pseudomonas aeruginosa
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Fan Yang, Yuchen Zhou, Yuxi Bai, Xiaolei Pan, Un-Hwan Ha, Zhihui Cheng, Weihui Wu, Yongxin Jin, and Fang Bai
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Microbiology (medical) ,Infectious Diseases ,General Immunology and Microbiology ,Ecology ,Physiology ,Genetics ,Cell Biology - Abstract
Antibiotic resistance imposes a considerable challenge for the treatment of P. aeruginosa infections. Polymyxins are the last-resort antibiotics for the treatment of multidrug-resistant P. aeruginosa infections.
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- 2023
12. Unravelling the relationship between perceived values-congruence with organizational change readiness: A moderated mediation model
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Jinzhao Deng, Zhihui Cheng, Siqi Qi, and Rich Deng
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General Psychology - Abstract
Recent studies have demonstrated that organizations often fail to execute organizational changes effectively due to a lack of their employees’ organizational change readiness (OCR). However, the absence of employees’ OCR is rooted in whether their values align with their organizations. The research aims to clarify when and why employees’ perceived values-congruence with their organizations, supervisors, and workgroups (PVC-O, PVC-S, and PVC-G) helps stimulate their organizational change readiness (OCR). Specifically, it Integrates the self-categorization theory and social information processing theory and proposes a moderated mediation model to investigate the roles of perceived insider status (PIS) and the quality of change communication (QCC). This study gathered a valid sample of 252 employees from six Chinese companies at three different time points, and performed the structural equation modeling and multiple regression to test the proposed research model. The results demonstrate that PVC-O, PVC-S, and PVC-G are all positively related to employees’ PIS, which further promotes their readiness for organizational change. Additionally, QCC strengthens not only the positive effect of employees’ PVC-O and PVC-G (except for PVC-S) on PIS but also the indirect effects of PIS. This study offers valuable implications for practitioners implementing their organizational change practices in China. Moreover, this study can contribute to the organizational change literature by uncovering the underlying mechanism between perceived values-congruence and employees’ OCR in the light of the person-environment interaction.
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- 2023
13. Delivery of spike-RBD by bacterial type three secretion system for SARS-CoV-2 vaccine development
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Yuchen Zhou, Jing Qu, Xiaomeng Sun, Zhuo Yue, Yingzi Liu, Keli Zhao, Fan Yang, Jie Feng, Xiaolei Pan, Yongxin Jin, Zhihui Cheng, Liang Yang, Un-Hwan Ha, Weihui Wu, Liang Li, and Fang Bai
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Immunology ,Immunology and Allergy - Abstract
COVID-19 pandemic continues to spread throughout the world with an urgent demand for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a bacterial vector COVID-19 vaccine (aPA-RBD) that carries the gene for the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Live-attenuated strains of Pseudomonas aeruginosa (aPA) were constructed which express the recombinant RBD and effectively deliver RBD protein into various antigen presenting cells through bacterial type 3 secretion system (T3SS) in vitro. In mice, two-dose of intranasal aPA-RBD vaccinations elicited the development of RBD-specific serum IgG and IgM. Importantly, the sera from the immunized mice were able to neutralize host cell infections by SARS-CoV-2 pseudovirus as well as the authentic virus variants potently. T-cell responses of immunized mice were assessed by enzyme-linked immunospot (ELISPOT) and intracellular cytokine staining (ICS) assays. aPA-RBD vaccinations can elicit RBD-specific CD4+and CD8+T cell responses. T3SS-based RBD intracellular delivery heightens the efficiency of antigen presentation and enables the aPA-RBD vaccine to elicit CD8+T cell response. Thus, aPA vector has the potential as an inexpensive, readily manufactured, and respiratory tract vaccination route vaccine platform for other pathogens
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- 2023
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14. Pseudomonas aeruginosa Citrate Synthase GltA Influences Antibiotic Tolerance and the Type III Secretion System through the Stringent Response
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Hao Chen, Xuetao Gong, Zheng Fan, Yushan Xia, Yongxin Jin, Fang Bai, Zhihui Cheng, Xiaolei Pan, and Weihui Wu
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Microbiology (medical) ,Infectious Diseases ,General Immunology and Microbiology ,Ecology ,Physiology ,Genetics ,Cell Biology - Abstract
Carbohydrate metabolism plays essential roles in energy generation and providing carbon skeletons for amino acid syntheses. In addition, carbohydrate metabolism has been shown to influence bacterial susceptibility to antibiotics and virulence. In this study, we demonstrate that citrate synthase
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- 2023
15. Are 2D Interfaces Really Flat?
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Zhihui Cheng, Huairuo Zhang, Son T. Le, Hattan Abuzaid, Guoqing Li, Linyou Cao, Albert V. Davydov, Aaron D. Franklin, and Curt A. Richter
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General Engineering ,General Physics and Astronomy ,General Materials Science - Abstract
Two-dimensional (2D) van der Waals materials are subject to mechanical deformation and thus forming bubbles and wrinkles during exfoliation and transfer. A lack of interfacial "flatness" has implications for interface properties, such as those formed by metal contacts or insulating layers. Therefore, an understanding of the detailed properties of 2D interfaces, especially their flatness under different conditions, is of high importance. Here we use cross-sectional scanning transmission electron microscopy (STEM) to investigate various 2D interfaces (2D-2D and 3D-2D) under the effects of stacking, atomic layer deposition (ALD), and metallization. We characterize and compare the flatness of the hBN-2D and metal-2D interfaces down to angstrom resolution. It is observed that the dry transfer of hexagonal boron nitride (hBN) can dramatically alter the interface structure. When characterizing 3D metal-2D interfaces, we find that Ni-MoS
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- 2022
16. Binary mixing of lithospheric mantle and asthenosphere beneath Tengchong volcano, SE Tibet: evidence from noble gas isotopic signatures
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Kefei Chen, Huaiyu He, Finlay Stuart, Shaolin Liu, Xiwei Xu, Zhihui Cheng, Dinghui Yang, Jiyong Li, Fei Su, and Wenshuai Wang
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Geology - Published
- 2022
17. Biochemical and Physiological Responses of Cucumis sativus Cultivars to Different Combinations of Low-Temperature and High Humidity
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Bakht Amin, Muhammad Jawaad Atif, Huanwen Meng, Muhammad Imran Ghani, Muhammad Ali, Xiao Wang, Yuanyuan Ding, Xiuju Li, and Zhihui Cheng
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Plant Science ,Agronomy and Crop Science - Published
- 2022
18. Enhancement of a prime editing system via optimal recruitment of the pioneer transcription factor P65
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Ronghao Chen, Yu Cao, Yajing Liu, Dongdong Zhao, Ju Li, Zhihui Cheng, Changhao Bi, and Xueli Zhang
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Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
Prime editing is a versatile gene editing tool that enables precise sequence changes of all types in the genome, but its application is rather limited by the editing efficiency. Here, we first apply the Suntag system to recruit the transcription factor P65 and enhance the desired editing outcomes in the prime editing system. Next, MS2 hairpins are used to recruit MS2-fused P65 and confirmed that the recruitment of the P65 protein could effectively improve the prime editing efficiency in both the PE3 and PE5 systems. Moreover, this suggests the increased editing efficiency is most likely associated with the induction of chromatin accessibility change by P65. In conclusion, we apply different systems to recruit P65 and enhance the prime editing efficiency of various PE systems. Furthermore, our work provides a variety of methods to work as protein scaffolds for screening target factors and thus supports further optimization of prime editing systems.
- Published
- 2023
19. Genome-wide identification of small heat shock protein (HSP20) homologs in three cucurbit species and the expression profiles of CsHSP20s under several abiotic stresses
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Zhihui Cheng, Birong Chen, Chengchen Zhi, Lijun Qiao, Yupeng Pan, Yujie Zheng, Xi'ao Wang, and Ce Liu
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Melon ,Biology ,Biochemistry ,Genome ,Chromosomes, Plant ,Protein Structure, Secondary ,Species Specificity ,Gene Expression Regulation, Plant ,Stress, Physiological ,Structural Biology ,Gene Duplication ,Heat shock protein ,Gene family ,Amino Acid Sequence ,Nucleotide Motifs ,Promoter Regions, Genetic ,Molecular Biology ,Gene ,Conserved Sequence ,Phylogeny ,Plant Proteins ,Abiotic component ,Comparative genomics ,Genetics ,Sequence Homology, Amino Acid ,Phylogenetic tree ,Gene Expression Profiling ,food and beverages ,General Medicine ,Heat-Shock Proteins, Small ,Cucurbitaceae ,MicroRNAs ,Gene Ontology ,Organ Specificity ,Genome, Plant ,Subcellular Fractions - Abstract
Small heat shock protein (HSP20) genes play important roles in biological processes of plants. In this study, a total of 47 CsHSP20 genes, 45 CmHSP20 genes, and 47 ClHSP20 genes were genome-wide identified by 'hmmsearch' and BLASTP using the latest versions of cucumber, melon, and watermelon genomes, respectively. According to the phylogenetic relationships and predicted subcellular localizations, HSP20s of these three cucurbit species were divided into 8 subfamilies (CI-CIV, CP, ER, M, and PX), in which some HSP20s were closely related with each other based on the collinearity analysis. Specific expression patterns of CsHSP20s were checked in 10 different tissues of cucumber plants. RNA-seq analysis of transcript levels, combined with cis-acting elements and GO enrichment analysis suggested that CsHSP20s were responsive to several different types of abiotic stresses, including chilling, temperature and photoperiod, high temperature and high humidity, and salinity. In conclusion, results of this work not only provided valuable information for exploring the regulating mechanisms of CsHSP20s in responding to abiotic stresses in cucumber, but also shed light on the potentially evolutional relations among cucumber, melon, and watermelon from a perspective of comparative genomics that specified on HSP20 gene families.
- Published
- 2021
20. CtrA activates the expression of glutathione S-transferase conferring oxidative stress resistance to Ehrlichia chaffeensis
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Qi’an Liang, Jiaqi Yan, Shuwen Zhang, Nan Yang, Meifang Li, Yongxin Jin, Fang Bai, Weihui Wu, and Zhihui Cheng
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Microbiology (medical) ,Infectious Diseases ,Immunology ,Microbiology - Abstract
Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (HME), is a Gram-negative obligatory intracellular bacterium, which infects and multiplies in human monocytes and macrophages. Host immune cells produce reactive oxygen species (ROS) to eliminate E. chaffeensis upon infection. E. chaffeensis global transcriptional regulator CtrA activates the expression of GshA and GshB to synthesize glutathione (GSH), the most potent natural antioxidant, upon oxidative stress to combat ROS damage. However, the mechanisms exploited by E. chaffeensis to utilize GSH are still unknown. Here, we found that in E. chaffeensis CtrA activated the expression of glutathione S-transferase (GST) upon oxidative stress, and E. chaffeensis GST utilizes GSH to eliminate ROS and confers the oxidative stress resistance to E. chaffeensis. We found that CtrA bound to the promoter regions of 211 genes, including gst, in E. chaffeensis using chromatin immunoprecipitation coupled to deep sequencing (ChIP-seq). Recombinant E. chaffeensis CtrA directly bound to the gst promoter region determined with electrophoretic mobility shift assay (EMSA), and activated the gst expression determined with reporter assay. Recombinant GST showed GSH conjugation activity towards its typical substrate 2,4-dinitrochlorobenzene (CDNB) in vitro and peptide nucleic acid (PNA) transfection of E. chaffeensis, which can knock down the gst transcription level, reduced bacterial survival upon oxidative stress. Our results demonstrate that E. chaffeensis CtrA regulates GSH utilization, which plays a critical role in resistance to oxidative stress, and aid in the development of new therapeutics for HME.
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- 2022
21. Pseudomonas aeruginosa Phosphate Transporter PitA (PA4292) Controls Susceptibility to Aminoglycoside Antibiotics by Regulating the Proton Motive Force
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Xinrui Zhao, Yongxin Jin, Fang Bai, Zhihui Cheng, Weihui Wu, and Xiaolei Pan
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Pharmacology ,Infectious Diseases ,Adenosine Triphosphate ,Aminoglycosides ,Susceptibility ,Pseudomonas aeruginosa ,Escherichia coli ,Phosphate Transport Proteins ,Proton-Motive Force ,Pharmacology (medical) ,beta-Lactams ,Anti-Bacterial Agents ,Phosphates - Abstract
Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium that causes nosocomial infections in immunocompromised patients. β-lactam and aminoglycoside antibiotics are commonly used in the treatment of P. aeruginosa infections. Previously, we found that mutation in a PA4292 gene increases bacterial resistance to β-lactam antibiotics. In this study, we demonstrated that mutation in PA4292 increases bacterial susceptibility to aminoglycoside antibiotics. We further found enhanced uptake of tobramycin by the ΔPA4292 mutant, which might be due to an increase of proton motive force (PMF). Sequence analysis revealed PA4292 is homologous to the Escherichia coli phosphate transporter PitA. Mutation of PA4292 indeed reduces intracellular phosphate concentration. We thus named PA4292 as pitA. Although the PMF is enhanced in the ΔpitA mutant, the intracellular ATP concentration is lower than that in the isogenic wild-type strain PA14, which might be due to lack of the ATP synthesis substrate phosphate. Overexpression of the phosphate transporter complex genes pstSCAB in the ΔpitA mutant restores the intracellular phosphate concentration, PMF, ATP synthesis, and aminoglycosides resistance. In addition, growth of wild-type PA14 in a low-phosphate medium resulted in higher PMF and aminoglycoside susceptibility compared to cells grown in a high-phosphate medium. Overall, our results demonstrate the roles of PitA in phosphate transportation and reveal the relationship between intracellular phosphate and aminoglycoside susceptibility.
- Published
- 2022
22. Research on emergency treatment technology for water pollution accidents where the pollutants are not included in the emergency database
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Junwen Chen, Zhengjiang Lin, Zhihui Cheng, Ying Liu, and Yu Chen
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Pollution ,Technology ,Environmental Engineering ,critic-ew ,Computer science ,media_common.quotation_subject ,computer.software_genre ,Environmental technology. Sanitary engineering ,Set (abstract data type) ,Entropy (information theory) ,Water pollution ,Emergency Treatment ,similarity ,TD1-1066 ,emergency treatment technology ,Water Science and Technology ,media_common ,Pollutant ,Database ,Water Pollution ,TOPSIS ,Ideal solution ,hflts-topsis ,Accidents ,Environmental Pollutants ,computer ,Alternative technology - Abstract
At present, emergency treatment methods are selected based on case or technical database, and it is limited to chemicals in pollution accidents covered by the database. Based on the existing emergency treatment technical database, this paper adds a new chemical characteristics database from the physicochemical properties of chemicals such as toxicity and solubility. Combining the weight of characteristic indexes calculated by the Criteria Importance Though Intercriteria Correlation method combined with the Entropy Weight (CRITIC-EW) method and Manhattan distance, a model is constructed to preliminarily select alternative technologies for a target pollutant. Then, Decision-Makers (DMs) can evaluate alternative technologies using the compound language combined comparative language based on hesitant fuzzy linguistic term set (HFLTS) and single language. And alternative technologies are ranked by applying Technique for order performance by similarity to ideal solution (TOPSIS) method. The closest alternative technology is the most suitable. Taking Bisphenol A (BPA) pollution accident as an example, this method is verified. By analyzing physicochemical properties, forms, and uses between similar chemicals and BPA, as well as applicability of alternative technologies, the emergency treatment method proposed in this study is proved feasible. HIGHLIGHTS Constructed a system to search emergency treatment technology when a pollutant is not included in the existing database.; Proposed the CRITIC method combined with the Entropy Weight method (CRITIC-EW method) to calculate objective weights.; Proposed the compound language combined comparative language based on hesitant fuzzy linguistic term set (HFLTS) and single language to evaluate alternative technologies.
- Published
- 2021
23. Unanticipated Polarity Shift in Edge-Contacted Tungsten-Based 2D Transition Metal Dichalcogenide Transistors
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Aaron D. Franklin, Hattan Abuzaid, Guoqing Li, Zhihui Cheng, and Linyou Cao
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Materials science ,Ion beam ,business.industry ,Transistor ,chemistry.chemical_element ,Substrate (electronics) ,Tungsten ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry ,Transition metal ,law ,Etching ,Miniaturization ,Optoelectronics ,Field-effect transistor ,Electrical and Electronic Engineering ,business - Abstract
Creating metal edge contacts in transition metal dichalcogenide (TMD) transistors is a promising path to advance transistor miniaturization for future technology nodes. Current experimental demonstrations nearly exclusively focus on MoS2 as the channel material. Here, we create edge-contacted WSe2 and WS2 transistors using a convergent Ar+ ion beam source integrated within an e-beam evaporator chamber for in-situ processing. An unanticipated polarity shift was observed compared to top-contact behavior for Ti-WS2 devices, which displayed p-type conduction. Meanwhile, three distinct metal contact materials yielded comparable p-branch-dominant performance on WSe2. Transmission electron microscope (TEM) imaging with energy dispersive spectroscopy (EDS) analysis indicated the existence of a residual layer of W (and chalcogen atoms to a lesser extent) beneath the metal contacts, even though the substrate was over-etched. The images presented a physically pure edge interface. This intriguing etching effect could carry significant implications for the design of tungsten-based, edge-contacted TMD transistors.
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- 2021
24. Reversion of Ceftazidime Resistance in
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Qi, Liu, Liwen, Yin, Xinxin, Zhang, Guangbo, Zhu, Huimin, Liu, Fang, Bai, Zhihui, Cheng, Weihui, Wu, and Yongxin, Jin
- Published
- 2022
25. CtrA activates the expression of glutathione S-transferase conferring oxidative stress resistance to
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Qi'an, Liang, Jiaqi, Yan, Shuwen, Zhang, Nan, Yang, Meifang, Li, Yongxin, Jin, Fang, Bai, Weihui, Wu, and Zhihui, Cheng
- Published
- 2022
26. Development of Resistance to Eravacycline by Klebsiella pneumoniae and Collateral Sensitivity-Guided Design of Combination Therapies
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Congjuan Xu, Xiaoya Wei, Yongxin Jin, Fang Bai, Zhihui Cheng, Shuiping Chen, Xiaolei Pan, and Weihui Wu
- Subjects
Proteomics ,Microbiology (medical) ,Protease La ,General Immunology and Microbiology ,Ecology ,Physiology ,Porins ,Drug Collateral Sensitivity ,Microbial Sensitivity Tests ,Cell Biology ,beta-Lactamases ,Anti-Bacterial Agents ,Klebsiella Infections ,Mice ,Klebsiella pneumoniae ,Aztreonam ,Infectious Diseases ,Carbapenems ,Tetracyclines ,Genetics ,Animals ,beta-Lactamase Inhibitors ,Azabicyclo Compounds - Abstract
The evolution of bacterial antibiotic resistance is exhausting the list of currently used antibiotics and endangers those in the pipeline. The combination of antibiotics is a promising strategy that may suppress resistance development and/or achieve synergistic therapeutic effects. Eravacycline is a newly approved antibiotic that is effective against a variety of multidrug-resistant (MDR) pathogens. However, the evolution of resistance to eravacycline and strategies to suppress the evolution remain unexplored. Here, we demonstrated that a carbapenem-resistant Klebsiella pneumoniae clinical isolate quickly developed resistance to eravacycline, which is mainly caused by mutations in the gene encoding the Lon protease. The evolved resistant mutants display collateral sensitivities to β-lactam/β-lactamase inhibitor (BLBLI) combinations aztreonam/avibactam and ceftazidime-avibactam. Proteomic analysis revealed upregulation of the multidrug efflux system AcrA-AcrB-TolC and porin proteins OmpA and OmpU, which contributed to the increased resistance to eravacycline and susceptibility to BLBLIs, respectively. The combination of eravacycline with aztreonam/avibactam or ceftazidime-avibactam suppresses resistance development. We further demonstrated that eravacycline-resistant mutants evolved from an NDM-1-containing K. pneumoniae strain display collateral sensitivity to aztreonam/avibactam, and the combination of eravacycline with aztreonam/avibactam suppresses resistance development. In addition, the combination of eravacycline with aztreonam/avibactam or ceftazidime-avibactam displayed synergistic therapeutic effects in a murine cutaneous abscess model. Overall, our results revealed mechanisms of resistance to eravacycline and collateral sensitivities to BLBLIs and provided promising antibiotic combinations in the treatment of multidrug-resistant K. pneumoniae infections.
- Published
- 2022
27. Phenotypic Characterization and Fine Mapping of a Major-Effect Fruit Shape QTL
- Author
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Yupeng, Pan, Birong, Chen, Lijun, Qiao, Feifan, Chen, Jianyu, Zhao, Zhihui, Cheng, and Yiqun, Weng
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Phenotype ,Indoleacetic Acids ,Fruit ,Quantitative Trait Loci ,Chromosome Mapping ,Cucumis sativus - Abstract
Cucumber (
- Published
- 2022
28. High-Level Expression of Cell-Surface Signaling System Hxu Enhances Pseudomonas aeruginosa Bloodstream Infection
- Author
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Fan Yang, Yuchen Zhou, Peishan Chen, Zeqiong Cai, Zhuo Yue, Yongxin Jin, Zhihui Cheng, Weihui Wu, Liang Yang, Un-Hwan Ha, and Fang Bai
- Subjects
Haptoglobins ,Virulence Factors ,Iron ,Immunology ,Bacterial Infections ,Heme ,Microbiology ,Mice ,Hemoglobins ,Infectious Diseases ,Bacterial Proteins ,Hemopexin ,Sepsis ,Pseudomonas aeruginosa ,Animals ,Transferrins ,Parasitology ,Pseudomonas Infections ,Signal Transduction - Abstract
Bloodstream infections (BSIs) caused by Pseudomonas aeruginosa are associated with a high mortality rate in the clinic. However, the fitness mechanisms responsible for the evolution of virulence factors that facilitate the dissemination of P. aeruginosa to the bloodstream are poorly understood. In this study, a transcriptomic analysis of the BSI-associated P. aeruginosa clinical isolates showed a high-level expression of cell-surface signaling (CSS) system Hxu. Whole-genome sequencing and comparative genomics of these isolates showed that a mutation in rnfE gene was responsible for the elevated expression of the Hxu-CSS pathway. Most importantly, deletion of the hxuIRA gene cluster in a laboratory strain PAO1 reduced its BSI capability while overexpression of the HxuIRA pathway promoted BSI in a murine sepsis model. We further demonstrated that multiple components in the blood plasma, including heme, hemoglobin, the heme-scavenging proteins haptoglobin, and hemopexin, as well as the iron-delivery protein transferrin, could activate the Hxu system. Together, these studies suggested that the Hxu-CSS system was an important signal transduction pathway contributing to the adaptive pathogenesis of P. aeruginosa in BSI.
- Published
- 2022
29. Emergence and Transfer of Plasmid-Harbored
- Author
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Jiacong, Gao, Xiaoya, Wei, Liwen, Yin, Yongxin, Jin, Fang, Bai, Zhihui, Cheng, and Weihui, Wu
- Abstract
Multidrug-resistant (MDR)
- Published
- 2022
30. Diffuse emission of CO2 from the Langjiu Geothermal Field, Western Tibet
- Author
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Yutao Sun, Zhengfu Guo, Danielle Fortin, Wenbin Zhao, Zhihui Cheng, Jujing Li, and Yue Zhang
- Subjects
Geochemistry and Petrology ,Economic Geology - Published
- 2023
31. Transcriptomic analysis of Cucumis sativus uncovers putative genes related to hormone signaling under low temperature (LT) and high humidity (HH) stress
- Author
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Bakht Amin, Muhammad Jawaad Atif, Yupeng Pan, Shabir A. Rather, Muhammad Ali, Shuju Li, and Zhihui Cheng
- Subjects
Genetics ,Plant Science ,General Medicine ,Agronomy and Crop Science - Published
- 2023
32. Promoting employees’ pro‐environmental behaviour through empowering leadership: The roles of psychological ownership, empowerment role identity, and environmental self‐identity
- Author
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Kong Zhou, Wenxing Liu, Yi Han, Zhihui Cheng, and Yujie Che
- Subjects
Organizational Behavior and Human Resource Management ,Economics and Econometrics ,Philosophy ,media_common.quotation_subject ,Role identity ,Identity (social science) ,Management, Monitoring, Policy and Law ,Business and International Management ,Psychology ,Empowerment ,Social psychology ,media_common - Published
- 2021
33. Linking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau
- Author
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Cong-Qiang Liu, Zhihui Cheng, Zhengfu Guo, Lihong Zhang, Ai-Ti Chen, Yunchao Lang, Si-Liang Li, Zhongping Li, Guodong Zheng, Yuji Sano, Ying Li, Maoliang Zhang, Peter H. Barry, Sæmundur A. Halldórsson, Sheng Xu, and Liwu Li
- Subjects
geography ,Multidisciplinary ,Plateau ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Earth science ,Science ,Tectonics ,General Physics and Astronomy ,Context (language use) ,Geology ,General Chemistry ,Geodynamics ,Fault (geology) ,010502 geochemistry & geophysics ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Mantle (geology) ,Article ,Geochemistry ,0105 earth and related environmental sciences - Abstract
The episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth., Deeply-sourced volatiles are releasing from orogenic plateau regions, providing windows to plateau growth dynamics occurring at variable depths. Here the authors show that mantle-derived volatiles reveal the involvement of mantle dynamics in southeastward growth of the Tibetan Plateau.
- Published
- 2021
34. Acetylation of the CspA family protein CspC controls the type III secretion system through translational regulation ofexsAinPseudomonas aeruginosa
- Author
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Xuetao Gong, Weihui Wu, Zhuo Yue, Xiaolei Pan, Zhihui Cheng, Yuding Weng, Yongxin Jin, Fang Bai, Xinxin Zhang, Shouyi Li, Xiaoxiao Li, and Zhouyi Chai
- Subjects
AcademicSubjects/SCI00010 ,Virulence ,Biology ,medicine.disease_cause ,Type three secretion system ,Mice ,03 medical and health sciences ,Bacterial Proteins ,Gene expression ,Translational regulation ,Pneumonia, Bacterial ,Type III Secretion Systems ,Genetics ,medicine ,Animals ,Humans ,Promoter Regions, Genetic ,Gene ,Heat-Shock Proteins ,030304 developmental biology ,Regulation of gene expression ,0303 health sciences ,030306 microbiology ,Pseudomonas aeruginosa ,Gene regulation, Chromatin and Epigenetics ,RNA ,Acetylation ,Gene Expression Regulation, Bacterial ,Cell biology ,A549 Cells ,Protein Biosynthesis ,Trans-Activators - Abstract
The ability to fine tune global gene expression in response to host environment is critical for the virulence of pathogenic bacteria. The host temperature is exploited by the bacteria as a cue for triggering virulence gene expression. However, little is known about the mechanism employed by Pseudomonas aeruginosa to response to host body temperature. CspA family proteins are RNA chaperones that modulate gene expression. Here we explored the functions of P. aeruginosa CspA family proteins and found that CspC (PA0456) controls the bacterial virulence. Combining transcriptomic analyses, RNA-immunoprecipitation and high-throughput sequencing (RIP-Seq), we demonstrated that CspC represses the type III secretion system (T3SS) by binding to the 5′ untranslated region of the mRNA of exsA, which encodes the T3SS master regulatory protein. We further demonstrated that acetylation at K41 of the CspC reduces its affinity to nucleic acids. Shifting the culture temperature from 25°C to 37°C or infection of mouse lung increased the CspC acetylation, which derepressed the expression of the T3SS genes, resulting in elevated virulence. Overall, our results identified the regulatory targets of CspC and revealed a regulatory mechanism of the T3SS in response to temperature shift and host in vivo environment.
- Published
- 2021
35. Effect of low temperature and high humidity stress on physiology of cucumber at different leaf stages
- Author
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Zhihui Cheng, Huanwen Meng, Bakht Amin, Xiuju Li, Muhammad Ali, Yuanyuan Ding, Xi'ao Wang, Muhammad Imran Ghani, and Muhammad Jawaad Atif
- Subjects
Chlorophyll ,0106 biological sciences ,Antioxidant ,Photosystem II ,medicine.medical_treatment ,Plant Science ,Biology ,Photosynthetic efficiency ,Photosynthesis ,010603 evolutionary biology ,01 natural sciences ,chemistry.chemical_compound ,medicine ,Ecology, Evolution, Behavior and Systematics ,Temperature ,Humidity ,General Medicine ,APX ,Plant Leaves ,Horticulture ,Point of delivery ,chemistry ,Shoot ,Cucumis sativus ,010606 plant biology & botany - Abstract
Low temperature (LT) and high humidity (HH) are important environmental factors in greenhouses and plastic tunnels during the cold season, as they hamper plant growth and development. Here, we studied the effect of LT (day/night: 9/5 °C, 25/18 °C as control) and HH (95%, 80% as control) on young cucumber plants at the 2, 4 or 6 leaf stages. LT+HH stress resulted in a decline in shoot, root and total fresh and dry weights, and decreased Pn , gs , Tr , Fv /Fm , qP, ETR and chlorophyll, and increased MDA, H2 O2 , O2 - , NPQ and Ci as compared to the control at the 2 leaf stage. SOD, POD, CAT, APX and GR were upregulated under LT+HH stress as compared to the control at the 6 leaf stage. ABA and JA increased under LT+HH stress as compared to the control at the 6 leaf stage, while IAA and GA decreased under LT+HH stress as compared to the control at the 2 leaf stage. Our results show that LT+HH stress affects young cucumber plant photosynthetic efficiency, PSII activity, antioxidant defence system, ROS and hormone profile. Plants at the 6 leaf stage were more tolerant than at the 2 and 4 leaf stages under stress conditions.
- Published
- 2021
36. Mutation of PA4292 in Pseudomonas aeruginosa Increases β-Lactam Resistance through Upregulating Pyocyanin Production
- Author
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Xinrui Zhao, Yongxin Jin, Fang Bai, Zhihui Cheng, Weihui Wu, and Xiaolei Pan
- Subjects
Pharmacology ,Microbial Sensitivity Tests ,beta-Lactams ,beta-Lactam Resistance ,beta-Lactamases ,Anti-Bacterial Agents ,Aztreonam ,Infectious Diseases ,Mechanisms of Resistance ,Mutation ,Pseudomonas aeruginosa ,Pyocyanine ,Pharmacology (medical) ,beta-Lactamase Inhibitors ,Azabicyclo Compounds - Abstract
Metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa is increasingly reported worldwide and usually causes infections with high mortality rates. Aztreonam/avibactam is a β-lactam/β-lactamase inhibitor (BLBLI) combination that is under clinical trials. The advantage of aztreonam/avibactam over the currently used BLBLIs lies in its effectiveness against MBL-producing pathogens, making it one of the few drugs that can be used to treat infections caused by MBL-producing P. aeruginosa. However, the molecular mechanisms underlying aztreonam/avibactam resistance development remain unexplored. Here, in this study, we performed an in vitro evolution assay by using a previously identified MBL-producing P. aeruginosa clinical isolate, NKPa-71, and found mutations in a novel gene, PA4292, in the aztreonam/avibactam-resistant mutants. By mutation of PA4292 in the reference strain PA14, we verified the role of PA4292 in the resistance to aztreonam/avibactam and β-lactams. Transcriptomic analyses revealed upregulation of pyocyanin biosynthesis genes among the most overexpressed in the PA4292 mutant. We further demonstrated that pyocyanin overproduction in the PA4292 mutant increased the bacterial resistance to β-lactams by reducing drug influx. These data revealed a novel mechanism that might lead to the development of resistance to aztreonam/avibactam and β-lactams.
- Published
- 2022
37. Acetylation of CspC Controls the Las Quorum-Sensing System through Translational Regulation of rsaL in Pseudomonas aeruginosa
- Author
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Shouyi Li, Xuetao Gong, Liwen Yin, Xiaolei Pan, Yongxin Jin, Fang Bai, Zhihui Cheng, Un-Hwan Ha, and Weihui Wu
- Subjects
Virology ,Microbiology - Abstract
Bacterial infectious diseases impose a severe threat to human health. The ability to orchestrate virulence determinant in response to the host environment is critical for the pathogenesis of bacterial pathogens. Pseudomonas aeruginosa is a leading pathogen that causes various infections in humans.
- Published
- 2022
38. Evolution of Resistance to Phenazine Antibiotics in Staphylococcus aureus and Its Role During Coinfection with Pseudomonas aeruginosa
- Author
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Hongfen Yang, Zheng Fan, Xinwen Zhang, Xiaolei Pan, Bo Fang, Fan Yang, Tongtong Fu, Baolin Sun, Zhao Cai, Liang Yang, Wuihui Wu, Zhihui Cheng, Robert W. Huigens, Fang Bai, Zhuo Yue, and Yongxin Jin
- Subjects
0301 basic medicine ,Chemistry ,Pseudomonas aeruginosa ,030106 microbiology ,Mutant ,Phenazine ,Repressor ,medicine.disease_cause ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Infectious Diseases ,Pyocyanin ,Staphylococcus aureus ,medicine ,Efflux ,Pathogen - Abstract
In the niches that Staphylococcus aureus and Pseudomonas aeruginosa coinhabit, the later pathogen produces phenazine antibiotics to inhibit the growth of S. aureus. Recently, a group of halogenated phenazines (HPs) has been shown to have potent antimicrobial activities against Staphylococci; however, no HP-resistant mutant has been reported. Here, we demonstrate that S. aureus develops HP-resistance via single amino acid change (Arg116Cys) in a transcriptional repressor TetR21. RNA-seq analysis showed that the TetR21R116C variation caused drastic up-regulation of an adjacent gene hprS (halogenated phenazine resistance protein of S. aureus). Deletion of the hprS in the TetR21R116C background restored bacterial susceptibility to HP, while hprS overexpression in S. aureus conferred HP-resistance. The expression of HprS is under tight transcriptional control of the TetR21 via direct binding to the promoter region of hprS. The R116C mutation in TetR21 significantly reduced its DNA binding affinity. Moreover, natural phenazine antibiotics (phenazine-1-carboxylic acid and pyocyanin) and a HP analog (HP-22) are ligands for the TetR21, regulating its repressor activity. Combining homology analysis and LC-MS/MS assay we demonstrated that HprS is a phenazine efflux pump. To the best of our knowledge, we provide the first report of phenazine efflux pump in S. aureus. Interestingly, the TetR21R116C variation has been found in some clinical S. aureus isolates, and a laboratory strain of S. aureus with TetR21R116C variation showed enhanced growth competitiveness toward P. aeruginosa and promoted coinfection with P. aeruginosa in the host environment, demonstrating significance of the mutation in host infections.
- Published
- 2021
39. Insights into the mechanism regulating the differential expression of the P28-OMP outer membrane proteins in obligatory intracellular pathogen Ehrlichia chaffeensis
- Author
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Xiaohui Ma, Zhouyi Chai, Weihui Wu, Yingxing Feng, Fang Bai, Heting Cui, Zhihui Cheng, Zhexuan Wang, Yongxin Jin, Xiaoxiao Li, Yu Cao, Nan Duan, Yasuko Rikihisa, and Jiaqi Yan
- Subjects
0301 basic medicine ,Ehrlichiosis ,Hot Temperature ,Epidemiology ,THP-1 Cells ,030106 microbiology ,Immunology ,Biology ,Microbiology ,Tr1 ,Intracellular pathogen ,03 medical and health sciences ,Ticks ,Bacterial Proteins ,Species Specificity ,Virology ,parasitic diseases ,Drug Discovery ,Consensus Sequence ,medicine ,Escherichia coli ,Ehrlichia chaffeensis ,Animals ,Humans ,Differential expression ,differential gene expression ,Promoter Regions, Genetic ,Mechanism (biology) ,General Medicine ,P28-OMP outer membrane proteins ,Gene Expression Regulation, Bacterial ,medicine.disease ,biology.organism_classification ,bacterial infections and mycoses ,human monocytic ehrlichiosis ,030104 developmental biology ,Infectious Diseases ,Parasitology ,Bacterial outer membrane ,Research Article ,Bacterial Outer Membrane Proteins ,Transcription Factors - Abstract
Ehrlichia chaffeensis causes human monocytic ehrlichiosis (HME), which is one of the most prevalent, life-threatening emerging infectious zoonoses. The life cycle of E. chaffeensis includes ticks and mammals, in which E. chaffeensis proteins are expressed differentially contributing to bacterial survival and infection. Among the E. chaffeensis P28-OMP outer membrane proteins, OMP-1B and P28 are predominantly expressed in tick cells and mammalian macrophages, respectively. The mechanisms regulating this differential expression have not been comprehensively studied. Here, we demonstrate that the transcriptional regulators EcxR and Tr1 regulate the differential expression of omp-1B and p28 in E. chaffeensis. Recombinant E. chaffeensis Tr1 bound to the promoters of omp-1B and p28, and transactivated omp-1B and p28 promoter-EGFP fusion constructs in Escherichia coli. The consensus sequence of Tr1 binding motifs was AC/TTATA as determined with DNase I footprint assay. Tr1 showed a higher affinity towards the p28 promoter than the omp-1B promoter as determined with surface plasmon resonance. EcxR activated the tr1 expression in response to a temperature decrease. At 37°C low level of Tr1 activated the p28 expression. At 25°C high level of Tr1 activated the omp-1B expression, while repressing the p28 expression by binding to an additional site upstream of the p28 gene. Our data provide insights into a novel mechanism mediated by Tr1 regulating E. chaffeensis differential gene expression, which may aid in the development of new therapeutics for HME.
- Published
- 2021
40. Salmonella Typhimurium reprograms macrophage metabolism via T3SS effector SopE2 to promote intracellular replication and virulence
- Author
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Lei Wang, Di Huang, Huan Zhang, Shuangshuang Ma, Haiyan Zhou, Lu Feng, Jiaqi Yan, Shuai Ma, Wanwu Li, Peisheng Wang, Zhihui Cheng, Runxia Lv, Jingting Wang, Xiaorui Song, Xiaoqian Liu, Lingyan Jiang, and Chen Yang
- Subjects
0301 basic medicine ,Salmonella typhimurium ,Genomic Islands ,Science ,General Physics and Astronomy ,Virulence ,Glyceric Acids ,General Biochemistry, Genetics and Molecular Biology ,Serine ,03 medical and health sciences ,Mice ,Bacterial Proteins ,Type III Secretion Systems ,Animals ,Guanine Nucleotide Exchange Factors ,Metabolomics ,Secretion ,Glycolysis ,Cellular microbiology ,Multidisciplinary ,030102 biochemistry & molecular biology ,Effector ,Chemistry ,Macrophages ,Comment ,General Chemistry ,Gene Expression Regulation, Bacterial ,Pathogenicity island ,Cell biology ,030104 developmental biology ,Glucose ,RAW 264.7 Cells ,bacteria ,Pathogens ,Phosphoenolpyruvate carboxykinase ,Infection ,Intracellular ,Signal Transduction - Abstract
Salmonella Typhimurium establishes systemic infection by replicating in host macrophages. Here we show that macrophages infected with S. Typhimurium exhibit upregulated glycolysis and decreased serine synthesis, leading to accumulation of glycolytic intermediates. The effects on serine synthesis are mediated by bacterial protein SopE2, a type III secretion system (T3SS) effector encoded in pathogenicity island SPI-1. The changes in host metabolism promote intracellular replication of S. Typhimurium via two mechanisms: decreased glucose levels lead to upregulated bacterial uptake of 2- and 3-phosphoglycerate and phosphoenolpyruvate (carbon sources), while increased pyruvate and lactate levels induce upregulation of another pathogenicity island, SPI-2, known to encode virulence factors. Pharmacological or genetic inhibition of host glycolysis, activation of host serine synthesis, or deletion of either the bacterial transport or signal sensor systems for those host glycolytic intermediates impairs S. Typhimurium replication or virulence. Salmonella Typhimurium establishes systemic infection by replicating in host macrophages. Here, Jiang et al. show that infected macrophages exhibit upregulated glycolysis and decreased serine synthesis, leading to accumulation of glycolytic intermediates that promote intracellular replication and virulence of S. Typhimurium.
- Published
- 2021
41. Improving Agrobacterium tumefaciens−Mediated Genetic Transformation for Gene Function Studies and Mutagenesis in Cucumber (Cucumis sativus L.)
- Author
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Hanqiang Liu, Jianyu Zhao, Feifan Chen, Zhiming Wu, Junyi Tan, Nhien Hao Nguyen, Zhihui Cheng, and Yiqun Weng
- Subjects
Cucumis sativus ,gene editing ,Genetics ,genetic transformation ,Agrobacterium tumefaciens ,T−DNA insertion mutagenesis ,cucumber ,Genetics (clinical) - Abstract
In the post−genomics era, Agrobacterium tumefaciens−mediated genetic transformation is becoming an increasingly indispensable tool for characterization of gene functions and crop improvement in cucumber (Cucumis sativus L.). However, cucumber transformation efficiency is still low. In this study, we evaluated the effects of several key factors affecting the shoot−regeneration rate and overall transformation efficiency in cucumber including genotypes, the age and sources of explants, Agrobacterium strains, infection/co−cultivation conditions, and selective agents. We showed that in general, North China cucumbers exhibited higher shoot−regeneration rate than US pickling or slicing cucumbers. The subapical ground meristematic regions from cotyledons or the hypocotyl had a similar shoot−regeneration efficiency that was also affected by the age of the explants. Transformation with the Agrobacterium strain AGL1 yielded a higher frequency of positive transformants than with GV3101. The antibiotic kanamycin was effective in selection against non−transformants or chimeras. Optimization of various factors was exemplified with the development of transgenic plants overexpressing the LittleLeaf (LL) gene or RNAi of the APRR2 gene in three cucumber lines. The streamlined protocol was also tested in transgenic studies in three additional genes. The overall transformation efficiency defined by the number of verified transgenic plants out of the number of seeds across multiple experiments was 0.2–1.7%. Screening among T1 OE transgenic plants identified novel, inheritable mutants for leaf or fruit color or size/shape, suggesting T−DNA insertion as a potential source of mutagenesis. The Agrobacterium−mediated transformation protocol from this study could be used as the baseline for further improvements in cucumber transformation.
- Published
- 2023
42. Mechanistic insights for efficient inactivation of antibiotic resistance genes: a synergistic interfacial adsorption and photocatalytic-oxidation process
- Author
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Guan Zhang, Zhurui Shen, Zhihui Cheng, John C. Crittenden, Mingmei Li, Sihui Zhan, Yi Li, and Zhiruo Zhou
- Subjects
Multidisciplinary ,Oxide ,Ultrafiltration ,Mineralization (soil science) ,010502 geochemistry & geophysics ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Membrane ,Adsorption ,chemistry ,Chemical engineering ,Wastewater ,Photocatalysis ,0105 earth and related environmental sciences - Abstract
Advanced oxidation processes (AOPs) have been applied to address multiple environmental concerns including antibiotic resistance genes (ARGs). ARGs have shown an increasing threat to human health, and they are either harbored by antibiotic-resistant bacteria (ARB) or free in the environment. However, the control of ARGs has been substantially limited by their low concentration and the limited knowledge about their interfacial behavior. Herein, a novel AOP catalyst, Ag/TiO2/graphene oxide (GO), combined with a polyvinylidene fluoride (PVDF) ultrafiltration membrane was designed with a synergistic interfacial adsorption and oxidation function to inactivate ARGs with high efficiency in both model solutions and in secondary wastewater effluent, especially when the residue concentration was low. Further analysis showed that the mineralization of bases and phosphodiesters mainly caused the inactivation of ARGs. Moreover, the interfacial adsorption and oxidation processes of ARGs were studied at the molecular level. The results showed that GO was rich in sp2 backbones and functional oxygen groups, which efficiently captured and enriched the ARGs via π-π interactions and hydrogen bonds. Therefore, the photogenerated active oxygen species attack the ARGs by partially overcoming the kinetic problems in this process. The Ag/TiO2/GO catalyst was further combined with a PVDF membrane to test its potential in wastewater treatment applications. This work offers an efficient method and a corresponding material for the inactivation and mineralization of intra/extracellular ARGs. Moreover, the molecular-level understanding of ARG behaviors on a solid–liquid interface will inspire further control strategies of ARGs in the future.
- Published
- 2020
43. Melatonin Rescues Photosynthesis and Triggers Antioxidant Defense Response in Cucumis sativus Plants Challenged by Low Temperature and High Humidity
- Author
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Bakht Amin, Muhammad Jawaad Atif, Huanwen Meng, Muhammad Ali, Shuju Li, Hesham F. Alharby, Ali Majrashi, Khalid Rehman Hakeem, and Zhihui Cheng
- Subjects
food and beverages ,Plant Science - Abstract
Environmental factors such as low temperature (LT) and high humidity (HH) hinder plant growth and development in plastic tunnels and solar greenhouses in the cold season. In this study, we examined the effect of melatonin (MT) on shoot-based tolerance to LT and HH conditions in cucumber (Cucumis sativus) seedlings and explored its underlying mechanism. LT and HH stress inhibited growth and biomass accumulation, produced leaf chlorosis, led to oxidative stress, lowered chlorophyll and carotenoid contents, reduced photosynthetic and photosystem II (PSII) activities, and increased the level of intercellular carbon dioxide and the non-photochemical quenching of photosystem I (PSI) and PSII. However, foliar application of MT significantly improved the morphological indices and photosynthetic efficiency of cucumber seedlings, which entailed the elevation of electrolyte leakage, lipid peroxidation, and reactive oxygen species accumulation by boosting the antioxidant enzyme defense system under LT and HH conditions. Additionally, the measurement of nitrogen (N), magnesium (Mg), and iron (Fe) contents in roots and leaves showed that MT significantly augmented the nutrient uptake of cucumber seedlings exposed to LT and HH stresses. Furthermore, MT application increased the transcripts levels of genes encoding antioxidant enzymes under LT and HH conditions, whereas treatment with LT and HH suppressed these genes, suggesting that MT application increases the LT and HH tolerance of cucumber seedlings. Overall, our results suggest that MT application increases the tolerance of cucumber seedlings to LT and HH stress by enhancing the plant morphometric parameters, regulating PSI and PSII, and activating the antioxidant defense mechanism. Thus, the exogenous application of MT could be potentially employed as a strategy to improve the LT and HH tolerance of cucumber.
- Published
- 2022
44. Neutrophil-mediated delivery of the combination of colistin and azithromycin for the treatment of bacterial infection
- Author
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Jiacong Gao, Xueyan Hu, Congjuan Xu, Mingming Guo, Shouyi Li, Fan Yang, Xiaolei Pan, Fangyu Zhou, Yongxin Jin, Fang Bai, Zhihui Cheng, Zhenzhou Wu, Shuiping Chen, Xinglu Huang, and Weihui Wu
- Subjects
Multidisciplinary - Abstract
Novel treatment strategies are in urgent need to deal with the rapid development of antibiotic-resistant superbugs. Combination therapies and targeted drug delivery have been exploited to promote treatment efficacies. In this study, we loaded neutrophils with azithromycin and colistin to combine the advantages of antibiotic combinations, targeted delivery, and immunomodulatory effect of azithromycin to treat infections caused by Gram-negative pathogens. Delivery of colistin into neutrophils was mediated by fusogenic liposome, while azithromycin was directly taken up by neutrophils. Neutrophils loaded with the drugs maintained the abilitity to generate reactive oxygen species and migrate.
- Published
- 2022
45. Dihydrolipoamide Acetyltransferase AceF Influences the Type III Secretion System and Resistance to Oxidative Stresses through RsmY/Z in Pseudomonas aeruginosa
- Author
-
Haozhou Li, Yushan Xia, Zhenyang Tian, Yongxin Jin, Fang Bai, Zhihui Cheng, Wieslaw Swietnicki, Weihui Wu, and Xiaolei Pan
- Subjects
Microbiology (medical) ,Pseudomonas aeruginosa ,AceF ,RsmY/Z ,sRNA ,hydrogen peroxide tolerance ,Virology ,bacteria ,biochemical phenomena, metabolism, and nutrition ,Microbiology - Abstract
Carbon metabolism plays an important role in bacterial physiology and pathogenesis. The type III secretion system (T3SS) of Pseudomonas aeruginosa is a virulence factor that contributes to acute infections. It has been demonstrated that bacterial metabolism affects the T3SS. Meanwhile, expression of T3SS genes is negatively regulated by the small RNAs RsmY and RsmZ. In this study, we studied the relationship between the dihydrolipoamide acetyltransferase gene aceF and the T3SS. Our results reveal an upregulation of RsmY and RsmZ in the aceF mutant, which represses the expression of the T3SS genes. Meanwhile, the aceF mutant is more tolerant to hydrogen peroxide. We demonstrate that the expression levels of the catalase KatB and the alkyl hydroperoxide reductase AhpB are increased in the aceF mutant. The simultaneous deletion of rsmY and rsmZ in the aceF mutant restored the expression levels of katB and ahpB, as well as bacterial susceptibility to hydrogen peroxide. Thus, we identify a novel role of AceF in the virulence and oxidative response of P. aeruginosa.
- Published
- 2022
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46. Pseudomonas aeruginosa Oligoribonuclease Controls Tolerance to Polymyxin B by Regulating Pel Exopolysaccharide Production
- Author
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Baopeng Yang, Yujun Jiang, Yongxin Jin, Fang Bai, Zhihui Cheng, and Weihui Wu
- Subjects
Pharmacology ,Infectious Diseases ,Bacterial Proteins ,Mechanisms of Resistance ,Exoribonucleases ,Pseudomonas aeruginosa ,Humans ,Pharmacology (medical) ,Polymyxins ,Anti-Bacterial Agents ,Polymyxin B - Abstract
Polymyxins are considered as the last resort antibiotics to treat infections caused by multidrug-resistant Gram-negative pathogens. Pseudomonas aeruginosa is an opportunistic pathogen that causes various infections in humans. Proteins involved in lipopolysaccharide modification and maintaining inner and outer membrane integrities have been found to contribute to the bacterial resistance to polymyxins. Oligoribonuclease (Orn) is an exonuclease that regulates the homeostasis of intracellular (3′–5′)-cyclic dimeric GMP (c-di-GMP), thereby regulating the production of extracellular polysaccharide in P. aeruginosa. Previously, we demonstrated that Orn affects the bacterial resistance to fluoroquinolone, β-lactam and aminoglycoside antibiotics. In this study, we found that mutation of orn increased the bacterial survival following polymyxin B treatment in a wild-type P. aeruginosa strain PA14. Overexpression of c-di-GMP degradation enzymes in the orn mutant reduced the bacterial survival. By using a fluorescence labeled polymyxin B, we found that mutation of orn increased the bacterial surface bound polymyxin B. Deletion of the Pel synthesis genes or treatment with a Pel hydrolase reduced the surface bound polymyxin B and bacterial survival. We further demonstrated that Pel binds to extracellular DNA (eDNA), which traps polymyxin B and thus protects the bacterial cells. Collectively, our results revealed a novel defense mechanism against polymyxin in P. aeruginosa.
- Published
- 2022
47. Genomic insights into the evolutionary history and diversification of bulb traits in garlic
- Author
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Ningyang Li, Xueyu Zhang, Xiudong Sun, Siyuan Zhu, Yi Cheng, Meng Liu, Song Gao, Jiangjiang Zhang, Yanzhou Wang, Xiai Yang, Jianrong Chen, Fu Li, Qiaoyun He, Zheng Zeng, Xiaoge Yuan, Zhiman Zhou, Longchuan Ma, Taotao Wang, Xiang Li, Hanqiang Liu, Yupeng Pan, Mengyan Zhou, Chunsheng Gao, Gang Zhou, Zhenlin Han, Shiqi Liu, Jianguang Su, Zhihui Cheng, Shilin Tian, and Touming Liu
- Subjects
Plant Breeding ,Genomics ,Garlic ,Polymorphism, Single Nucleotide ,Genome, Plant - Abstract
Background Garlic is an entirely sterile crop with important value as a vegetable, condiment, and medicine. However, the evolutionary history of garlic remains largely unknown. Results Here we report a comprehensive map of garlic genomic variation, consisting of amazingly 129.4 million variations. Evolutionary analysis indicates that the garlic population diverged at least 100,000 years ago, and the two groups cultivated in China were domesticated from two independent routes. Consequently, 15.0 and 17.5% of genes underwent an expression change in two cultivated groups, causing a reshaping of their transcriptomic architecture. Furthermore, we find independent domestication leads to few overlaps of deleterious substitutions in these two groups due to separate accumulation and selection-based removal. By analysis of selective sweeps, genome-wide trait associations and associated transcriptomic analysis, we uncover differential selections for the bulb traits in these two garlic groups during their domestication. Conclusions This study provides valuable resources for garlic genomics-based breeding, and comprehensive insights into the evolutionary history of this clonal-propagated crop.
- Published
- 2022
48. Molecular Characterization of WCK 5222 (Cefepime/Zidebactam)-Resistant Mutants Developed from a Carbapenem-Resistant Pseudomonas aeruginosa Clinical Isolate
- Author
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Xiaolei Pan, Xinrui Zhao, Yuqin Song, Huan Ren, Zhenyang Tian, Qi’an Liang, Yongxin Jin, Fang Bai, Zhihui Cheng, Jie Feng, and Weihui Wu
- Subjects
Microbiology (medical) ,Physiology ,Microbial Sensitivity Tests ,Ceftazidime ,beta-Lactamases ,Cyclooctanes ,Mice ,Bacterial Proteins ,Genetics ,Animals ,Humans ,Penicillin-Binding Proteins ,Pseudomonas Infections ,Mice, Inbred BALB C ,General Immunology and Microbiology ,Ecology ,Cell Biology ,Anti-Bacterial Agents ,Cephalosporins ,Drug Combinations ,Infectious Diseases ,Carbapenems ,Mutation ,Pseudomonas aeruginosa ,Female ,Azabicyclo Compounds - Abstract
WCK 5222 (cefepime/zidebactam) is a β-lactam/β-lactamase inhibitor combination that is effective against a broad range of highly drug-resistant bacterial pathogens, including those producing metallo-β-lactamase. In this study, we isolated a multidrug-resistant Pseudomonas aeruginosa clinical strain that is resistant to a variety of β-lactam antibiotics and the ceftazidime-avibactam combination. A metallo-β-lactamase gene
- Published
- 2022
49. NrtR Mediated Regulation of H1-T6SS in Pseudomonas aeruginosa
- Author
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Xinxin Zhang, Liwen Yin, Qi Liu, Dan Wang, Congjuan Xu, Xiaolei Pan, Fang Bai, Zhihui Cheng, Weihui Wu, and Yongxin Jin
- Subjects
Microbiology (medical) ,Transcription, Genetic ,Virulence ,General Immunology and Microbiology ,Ecology ,Virulence Factors ,Physiology ,Gene Expression Regulation, Bacterial ,Cell Biology ,Type VI Secretion Systems ,RNA, Bacterial ,Infectious Diseases ,Bacterial Proteins ,Operon ,Pseudomonas aeruginosa ,Type III Secretion Systems ,Genetics ,Promoter Regions, Genetic - Abstract
NrtR is a Nudix-related transcriptional regulator and controls the NAD cofactor biosynthesis in bacteria. P. aeruginosa NrtR binds to the intergenic region between nadD2 and pncA to repress the expression of the two operons, therefore controlling the NAD biosynthesis. We have previously reported that NrtR controls T3SS expression via the cAMP/Vfr pathway in P. aeruginosa .
- Published
- 2022
50. Garlic Allelochemical Diallyl Disulfide Alleviates Autotoxicity in the Root Exudates Caused by Long-Term Continuous Cropping of Tomato
- Author
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Fang Cheng, Muhammad Ali, Zhihui Cheng, Rui Deng, and Ce Liu
- Subjects
Chlorophyll ,Antioxidant ,Plant Exudates ,medicine.medical_treatment ,Autotoxicity ,Plant Roots ,Pheromones ,chemistry.chemical_compound ,Solanum lycopersicum ,Gene Expression Regulation, Plant ,medicine ,Disulfides ,Food science ,Photosynthesis ,Garlic ,Peroxidase ,Glutathione Disulfide ,biology ,Superoxide Dismutase ,Chemistry ,Diallyl disulfide ,fungi ,food and beverages ,General Chemistry ,Glutathione ,Allium sativum ,biology.organism_classification ,Crop Production ,Allyl Compounds ,Oxidative Stress ,Oleic acid ,biology.protein ,Solanum ,General Agricultural and Biological Sciences - Abstract
Continuous cropping obstacles seriously affect the sustainable production of tomatoes (Solanum lycopersicum L.). Researchers have found that intercropping with garlic (Allium sativum L.) could alleviate tomato continuous cropping obstacles. Diallyl disulfide (DADS) is the main allelochemical in garlic. However, the mechanism of DADS in alleviating tomato continuous cropping obstacles is still unknown. In this research, aqueous extracts of tomato continuous cropping soil were used to simulate the continuous cropping condition of tomato. Our results showed that DADS increased root activity and chlorophyll content and improved the activity of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and phenylalanine ammonia-lyase (PAL)) and the metabolism of nonenzymatic antioxidants (glutathione (GSH) and oxidized glutathione (GSSG)) in tomato plants. DADS treatment reduced the content of fatty acid esters in tomato root exudates (e.g., palmitate methyl ester, palmitoleic acid methyl ester, oleic acid methyl ester) and increased the level of substances such as dibutyl phthalate and 2,2'-methylenebis(6-tert-butyl-4-methylphenol). The higher concentrations of palmitate methyl ester inhibited tomato hypocotyl growth, while oleic acid methyl ester inhibited tomato root growth. Moreover, the application of DADS significantly inhibited the secretion of these esters in the root exudates. Therefore, it suggests that DADS may increase tomato resistance and promote tomato plant growth by increasing root activity and photosynthetic capacity and development to reduce autotoxicity of tomato.
- Published
- 2020
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