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Highlights • Response of MC-priming with improved salinity tolerance was cultivar specific. • Priming could develop different defense mechanisms in seeds against salinity. • Priming elevated water and Na+ uptake contribute to a better osmotic adjustment. • Priming regulated K+/Na+ homeostasis contribute to a higher tissue tolerance. Abstract The present study aimed to demonstrate the role of mepiquat chloride (MC) on the alleviation of the damaging effects of salinity on the germination of four cotton cultivars. Based on the ecophysiological data, CCRI44, CCRI49, and Z571 were less sensitive to salt stress and relied on a salt tolerance strategy to combat salinity at germination. Contrary to those salt-tolerance cultivars, seed germination of CZ91 was significantly inhibited by salt stress but most un-germinated seeds recovered completely when transferred to distilled water, indicating CZ91 follow a salt-avoiding strategy. Priming seeds with MC resulted in nullifying the negative effects of salt stress in salt-tolerance cultivars (especially in the cultivar Z571), but no significant response was observed in the salt-avoiding cultivar CZ91. At the mechanistic level, three complementary physiological traits are modulated by MC-priming upon exposure to salt stress: (i) better OA via increasing the water permeability and solute (i.e., Na+ or K+) mobility probably by regulating PIPs-regulated water channels; (ii) higher tissue tolerance ability via positively maintaining Na+ and K+ homeostasis by co-ordinated regulation of multiple ion transporters (e.g. SOS , HKT1 , NHX1 , AKT1 and HAK5); and (iii) further enhance the function of ion transport systems via inducing the gene expression of H+-ATPase. The strength of the three physiological traits varied among the MC pretreated cultivars, conferring differential ameliorating roles. Taken together, our observations confirmed that the effect of MC-priming on the alleviation of salinity stress is quite complex and dependent on the cultivar. It also shed light on transcriptional regulation of water and key ion transport systems involved in the maintenance of water absorption and K+/Na+ homeostasis as a key attribute for inducing salt tolerance by MC-priming in cotton cultivars. [ABSTRACT FROM AUTHOR]

Comparative analyses of torsional fretting, longitudinal fretting, and combined longitudinal and torsional fretting behaviors of steel wires were investigated in the present study. Hysteresis loops of tangential force versus displacement and torque versus torsion angle were explored employing the self-made test apparatus. Wear scars were quantitatively compared using the three-dimensional white light interferometer. Morphologies of wear scars of steel wires were comparatively analyzed to investigate their wear mechanisms employing the scanning electron microscope. Wear coefficients in all three cases were calculated and compared. The results show that the combined longitudinal and torsional fretting presents the largest relative slip (longitudinal and circumferential) and area of hysteresis loop. The wear scar size and wear coefficient of fatigue wire present the largest values in the case of combined longitudinal and torsional fretting as compared to the smallest values during torsional fretting. Meanwhile, combined longitudinal and torsional fretting exhibits the most severe damage at the contact surface. [ABSTRACT FROM AUTHOR]

A tension-torsion multiaxial fretting fatigue test apparatus was employed to investigate the effect of torsion angle on multiaxial fretting fatigue behaviors of steel wires in the present study. Working principals and structures of the test apparatus were introduced. Evolutions with fatigue loading of hysteresis loops of tangential force versus relative displacement between contacting wires, and torque versus torsion angle of steel wire were explored. Three-dimensional white light interferometer was used to measure the deflection angle and size of wear scar. Coefficients of friction during tests at distinct torsion angles were compared. Crack propagation characteristics of steel wires were explored employing the X-ray computed tomography. The results show that both types of hysteresis loops present overall increased loop areas with increasing torsion angle. An increase of torsion angle induces increased deflection angle and size of wear scar, coefficient of friction and maximum crack depth of steel wire, which reveals accelerated multiaxial fretting fatigue damage. [ABSTRACT FROM AUTHOR]

Previous studies have indicated that mechanical cotton harvesting requires a compact plant habit without fiber yield and quality reduction. The objective of this study was to determine the effects of planting date and plant density on plant habit, yield, early maturity, and fiber quality of cotton in the Yellow River valley region of China, and thus to identify the appropriate planting date and plant density suitable for its mechanical harvesting. Field experiments were conducted in 2013 and 2014 in Hejian, Hebei Province, using a split-plot design with planting date as the main plot and plant density as the subplot. The results indicated that moderately late planting in late April or early May (P2) was appropriate for mechanical harvesting of cotton as relative to P1 (local traditional planting date, 10 d earlier than P2) and P3 (10 d later than P2). P2 showed a 2.4–5.7 cm greater height to the first fruiting branch (from the bottom) and a 4.7–11.3 cm higher lowest boll (harvestable boll nearest to the ground) compared with P1, which is helpful for decreasing yield loss and reducing intake of residual plastic mulch. In addition, P2 produced slightly greater yield than P1 and P3, and the percentage of open bolls in late September for P2 was similar to that of P1 and greater than for P3, suggesting a low risk of late maturity. For plant density, 8.9 plants m −2 (D2) was appropriate for mechanical harvesting compared with 6.6 plants m −2 (D1), the local traditional density for manual harvesting, and 12.3 plants m −2 (D3). D2 showed a 2.5 cm greater height to the first fruiting branch and a 4.2 cm higher lowest boll, and exhibited 2.9–3.6 and 2.6–3.9 cm shorter lengths of lower and middle fruiting branches than D1, respectively. This type of compact plant habit is conducive to efficient mechanical harvesting. Moreover, D2 produced a similar yield to D1 for both the rainy 2013 and the dry 2014, indicating yield stability. Although D3 had a more suitable plant habit for mechanical cotton harvesting, its yield level and maturity varied across years. There were no significant interactions between planting date and plant density in the majority of tested traits. The results will contribute to the development of integrated cotton management for upcoming mechanical harvesting in the Yellow River valley region of China. [ABSTRACT FROM AUTHOR]

A multi-omics study was conducted on cotton seedlings to determine the growth promotion caused by mepiquat chloride (MC)-priming under salt stress. MC-priming markedly alleviated salt stress inhibition in root anatomical structures, increasing seedling establishment. Comparative multi-omics analyses revealed various energy metabolic pathways as key influencers of MC-priming, explaining the alleviation of salt stress. MC-priming up-regulated key proteins and phosphorylation for triacylglycerol (TAG) mobilization, γ-aminobutyric acid (GABA) shunt, and adenosine triphosphate (ATP) synthesis under salt stress. The coexpression network analyses also suggested that MC-priming regulates these metabolic pathways in a mutual-functioning fashion involving salt tolerance responses. Importantly, the inhibitor of β-oxidation and GABA-synthesis disrupted the MC-priming-induced growth under salt stress, confirming the importance of these pathways in forming the MC-priming response. MC-priming significantly blocked the salt-triggered TAG accumulation and early enhanced GABA shunt activities under salt stress. Meanwhile, MC-priming improved energy efficiency by up-regulating ATP synthase and down-regulating cytochrome b5-like reductase, thereby enhancing ATP formation and reducing reactive oxygen species production. In addition, MC-priming enhanced antioxidant enzymatic activities under salt stress. These findings provide insights into the energy regulatory pathway of MC-priming that mediates growth-promotion under salt stress. Thus, this study reinforces the potential of MC-priming to improve cotton seed germination under salt stress. • Mepiquat chloride (MC)–priming enhances cotton seedling establishment under salinity. • MC–priming activates TAG mobilization and GABA shunt pathways against salinity. • MC–priming also coordinately regulates electron transport chain against salinity. • Thus, MC–priming produces more ATP for cotton growth in response to salinity. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we have investigated the mutual and self coupling characteristics of directional couplers using two individual gain guided and index antiguided fibers, which can deliver robust single mode operation with large mode area, respectively owing to the combined adequately large gain coefficients in the core; Some interesting and distinguishing properties from conventional index guided fiber couplers are obtained that: The variations of coupling coefficients are complex-valued and spatially damping oscillated, but not exponential-like decreasing as conventional index guided couplers. [Copyright &y& Elsevier]

Dynamic wear evolution and crack propagation behaviors of steel wires during fretting-fatigue were investigated in this study. Wear scar and wear depth profiles of steel wires were quantitatively analyzed employing a three-dimensional white light interferometer. Theoretical models of maximum wear depth and wear coefficient of parabolic wear scars were established. Three-dimensional crack propagation characteristics of steel wires were presented using X-ray computed tomography. The results show that larger fatigue cycles induce decreased increase rates of elliptical wear scar area and parabolic wear depth of steel wires. An increase of relative displacement induces reduced damage and thereby better anti-wear properties of wires. The central zone of wear scar exhibits larger crack depth and faster crack propagation as compared to edge zones. [ABSTRACT FROM AUTHOR]

Effects of hoisting parameters (effective load, acceleration and deceleration) on dynamic contact characteristics between the rope and friction lining in a deep coal mine were analyzed in this study. Effects of hoisting parameters on dynamic tensions during hoisting with variable acceleration and deceleration were explored employing Simulink simulations. Roles of hoisting parameters on contact states, slip amplitude and stress distributions along the contact path were investigated using finite element analyses. The results show distinct tensions and tension differences at both rope ends with different hoisting parameters. Dynamic contact states consist of sticking, slip and mixed regimes during hoisting. Increases of hoisting parameters induce overall increased possibilities of the gross slip, increased stress concentrations and accelerated wear between contacting bodies. [ABSTRACT FROM AUTHOR]

• B. bronchiseptica aroA -deletion mutants (BbΔaroA) deliver different fragments of PMT. • Vaccination of BbΔaroA/PMTN and BbΔaroA/PMTC induced good humoral responses. • Vaccination of BbΔaroA/PMTN and BbΔaroA/PMTC induced high levels of sIgA. • BbΔaroA/PMTN and BbΔaroA/PMTC confer greater than 80% protection against Bb and PMT challenge. • BbΔaroA/PMTN showed better immunization effects than BbΔaroA/PMTC. Dermonecrotic toxin (DNT) is an important bacterial virulence factor produced by the zoonotic pathogens Bordetella bronchiseptica and Pasteurella multocida. This study aims to explore the possibility of expressing different fragments of P. multocida toxin (PMT) in the chromosome of attenuated B. bronchiseptica to generate single-component mucosal vaccine candidates. To achieve this, a 954-bp fragment (basepairs 301 ∼ 1254) of the B. bronchiseptica aroA gene was replaced with an N-terminal, 930-bp fragment (basepairs 1–930; PMTN) or a C-terminal, 900-bp fragment (base pairs 2959 ∼ 3858; PMTC) of the PMT encoding gene toxA. The resulting strains, denoted as Bb-PMTN or Bb-PMTC, expressed PMTN and PMTC, as evidenced by ELISA using polyclonal against full-length of PMT. Phenotypical analyses revealed that Bb-PMTN and Bb-PMTC grew much slower than wild type strains in tryptic soy broth. These strains also displayed significantly decreased 161-fold-virulence compared to the wildtype strains in mouse models. Intranasal immunization of Bb-PMTN and Bb-PMTC in mice induced high levels of antibodies against B. bronchiseptica and PMT, as well as IFN-γ and IL-10 in mouse sera, and most importantly, high titers of sIgA in mouse lungs. Vaccination with these two engineering strains provided 100% protection of mice against lethal challenge with B. bronchiseptica and 80%∼100% protection against lethal challenge with PMT, with Bb-PMTN exhibiting 1.25-fold greater immunogenic efficacy over Bb-PMTC. This study highlights the use of B. bronchiseptica attenuated strains as live mucosal vectors to deliver heterologous antigens. [ABSTRACT FROM AUTHOR]

• L-10 exhibited excellent antibacterial activity against MDR Gram-negative pathogens with limited resistance development. • L-10 remarkably damaged bacterial membrane integrity by targeting the bacterial membrane components, LPS and PG. • Therapeutic doses of L -10 displayed great efficacy in infection-associated animal models. • L-10 expressed in Pichia pastoris similarly maintained antimicrobial activity against MDR Gram-negative pathogens in vivo and in vitro. Antimicrobial resistance has raised concerns regarding untreatable infections and poses a growing threat to public health. Rational design of new AMPs is an ideal solution to this threat. In this study, we designed, modified, and synthesised an excellent AMP, L -10, based on the original sequence of the Cyprinus carpio chemokine. All experimental data were presented as the mean ± standard deviation (SD), and the two-tailed unpaired T-test method was used to analyze all data. L-10 exhibited excellent antibacterial activity with negligible toxicity and improved the efficacy of a broad class of antibiotics against MDR Gram-negative pathogens, including tetracycline, meropenem, levofloxacin, and rifampin. Mechanistic studies have suggested that L -10 targets the bacterial membrane components, LPS and PG, to disrupt bacterial membrane integrity, thereby exerting antibacterial effects and enhancing the efficacy of antibiotics. Moreover, in animal infection models, L -10 significantly increased the survival rate of infected animals and effectively reduced the tissue bacterial load and inflammatory factor levels. In addition to its direct antibacterial activity, L -10 dramatically reduced pulmonary pathological alterations in a mouse model of endotoxemia and suppressed LPS-induced proinflammatory cytokines in vitro and in vivo. Lastly, L -10 was successfully expressed in Pichia pastoris and maintained antimicrobial activity against MDR Gram-negative pathogens in vivo and in vitro. Collectively, these results reveal the potential of L -10 as an ideal candidate against MDR bacterial infections and provide new insights into the design, development, and clinical application of AMPs. [Display omitted] [ABSTRACT FROM AUTHOR]

• Generation a double deletion mutant Marek's disease virus absence of both meq and lorf9 genes. • Double deletion mutant Marek's disease virus has similar growth characteristics with parental virus in vitro. • Double deletion mutant Marek's disease virus significantly reduced replication in vivo. • Double deletion of meq and lorf9 genes overcome lymphoid organ atrophy induced by meq-deletion Marek's disease virus. • Double deletion mutant Marek's disease virus is fully attenuated. Marek's disease virus (MDV) is a highly contagious alphaherpesvirus that causes rapid onset of T cell lymphomas in chickens. MDV continues to break through vaccinal immunity due to the emergence of highly virulent field strains. Earlier studies revealed that deletion of the meq gene from MDV results in attenuated vaccines that protect against disease when chickens are infected with highly virulent strains. However, meq -deleted viruses still retain the ability to induce lymphoid organ atrophy, which raises safety concerns. In an earlier study, we found that deletion of lorf9 counteracts this lymphoid organ atrophy. Here, we describe the generation of a double deletion mutant virus lacking virus-encoded meq and lorf9. In vitro studies revealed that during replication, the mutant virus had kinetic characteristics similar to the parental virus; however, in vivo the replication capability was significantly reduced. Results of animal studies revealed no obvious MDV-specific symptoms and lesions. Importantly, the double deletion mutant virus lost the capacity to induce lymphoid organ atrophy, which has been the main obstacle during development of a good vaccine candidate. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen sensors with fast response and recovery rate based on nanoporous palladium (Pd) and titanium dioxide (TiO 2) composite films supported by anodic aluminum oxide (AAO) template have been demonstrated. Nanoporous TiO 2 film was sprayed on the porous AAO templates, followed by Pd film deposited on TiO 2 layer by DC magnetron sputtering. We have researched the detection performance of the hydrogen sensors depending on different thickness of TiO 2 layer from 6 to 30 nm with keeping the thickness of Pd as 30 nm. The results have demonstrated the sensors with 10 nm thickness of TiO 2 achieve the best performance with a response/recovery time as short as 4/8s at 0.8% and 0.4% hydrogen concentration, respectively. The sensors exhibited very good performance under hydrogen concentrations from 0.4% to 1.8%. Highlights • Hydrogen sensors based on Pd/TiO 2 films supported by AAO have been designed. • Effect of TiO 2 thickness on the performance of hydrogen sensor has been studied. • A response/recovery time of 4/8s has been achieved. • Sensor exhibited good performance under hydrogen concentrations from 0.4% to 1.8%. • The exist of TiO 2 would facilitate the dissolution of hydrogen into Pd film. [ABSTRACT FROM AUTHOR]

Abstract Azimuthal fractal spiral zone plates (AFSZPs) with particular fractal characteristics are proposed which have the ability to increase the number of foci comparing with conventional spiral zone plates. The generated beams possess sequence of optical vortices along the propagation direction with preset resolution. Numerical simulations are carried out under plane wave illumination and the good performance of this fractal diffractive optical elements are verified experimentally based on a programmable phase-only liquid-crystal spatial light modulator (SLM). In addition, the effects on the axial irradiance and resolution of foci caused by variations of parameters are also presented. [ABSTRACT FROM AUTHOR]

Haemophilus parasuis is an opportunistic pathogen localized in the upper respiratory tracts of pigs, its infection begins from bacterial survival under complex conditions, like hyperosmosis, oxidative stress, phagocytosis, and sometimes antibiotics as well. The two-component signal transduction (TCST) system serves as a common stimulus-response mechanism that allows microbes to sense and respond to diverse environmental conditions via a series of phosphorylation reactions. In this study, we investigated the role of TCST system CpxRA in H. parasuis in response to different environmental stimuli by constructing the ΔcpxA and ΔcpxR single deletion mutants as well as the ΔcpxRA double deletion mutant from H. parasuis serotype 4 isolate JS0135. We demonstrated that H. parasuis TCST system CpxRA confers bacterial tolerance to stresses and bactericidal antibiotics. The CpxR was found to play essential roles in mediating oxidative stress, osmotic stresses and alkaline pH stress tolerance, as well as macrolide resistance (i.e. erythromycin), but the CpxA deletion did not decrease bacterial resistance to abovementioned stresses. Moreover, we found via RT-qPCR approach that HAPS_RS00160 and HAPS_RS09425, both encoding multidrug efflux pumps, were significantly decreased in erythromycin challenged ΔcpxR and ΔcpxRA mutants compared with wild-type strain JS0135. These findings characterize the role of the TCST system CpxRA in H. parasuis conferring stress response tolerance and bactericidal resistance, which will deepen our understanding of the pathogenic mechanism in H. parasuis . [ABSTRACT FROM AUTHOR]

• we proposed a novel method to realize reconfigurable optical multi-beams (ROMB). It supports user-defined dynamic beam arrangement including arbitrary beam number, arbitrary angle, and arbitrary power occupancy rate. • Practical scheme and experimental setup provide an innovative, reliable, and low-cost solution. It is consisting of a commercial spatial light modulator device of liquid crystal on silicon (LCOS)and a 4-f image system for precise spatial pixel alignment and co-modulation of amplitude and phase. • The average relative error between the experiment and simulation is less than 6% and the practical pointing accuracy is higher than 93.164%, also the maximum beam number is limited by diffraction angle range. With the purpose of meeting the increasing requirement of free-space optical networking, reconfigurable multiple beams are required from a single terminal. In this paper, we demonstrate the role of co-modulation of amplitude and phase on incident laser beam using such a liquid crystal spatial light modulator. It enables arbitrary beam number, arbitrary pointing angle, and power occupation with multiple beams of excellent performance on a relative error and standard derivation when using typical groups of examples. Both numerical simulations and experimental results are presented demonstrating reconfigurable multiple beams forming via liquid crystal on silicon. [ABSTRACT FROM AUTHOR]

Extraintestinal pathogenic Escherichia coli (ExPEC) can invade and colonize multiple extraintestinal tissues and can cause a wide range of infections; however the mechanisms of its pathogenicity are not well understood. Flagella contribute to the infection of E. coli strains by mediating adhesion and invasion. Our previous bioinformatic analysis revealed two flagella gene clusters in the genome of an ExPEC isolate, PCN033. One encodes the conventional flagellum system (Flag-1) and the other encodes the Flag-2 system, whose function is uncharacterized. Here we aimed to characterize these two flagellum systems and determine their contributions to the flagellum formation and certain pathogenicity-associated phenotypes. Our observations support the involvement of Flag-1 system, but not Flag-2 system, in the synthesis and maturation of the flagellum structure, and in mediating bacterial swimming and swarming. Moreover, flgD , which encodes a flagellar-hook scaffolding protein in the Flag-1 system, is required for flagellum assembly by influencing the production of FliC (flagellin). Deletion of flgD attenuated ExPEC strain PCN033 invasion and colonization in vivo , probably by affecting bacterial adhesion and invasion, and by reducing resistance to phagocytosis by circulating monocytes. In contrast, these phenotypes were not observed in the strain with deletion of lfgD , encoding the FlgD-like protein in the Flag-2 system. Taken together, these findings indicate that Flag-1 flagellum system is the determinative component of bacterial flagella that contributes to the infection. [ABSTRACT FROM AUTHOR]

Fast response hydrogen sensors operating at room temperature based on nanoporous palladium (Pd) films supported by treated anodic aluminum oxide (AAO) template have been demonstrated. It was found that the nanoporous Pd film had a quicker and reversible response by a 30-min pore-widening treatment of the AAO template, due to its faster absorption and desorption of hydrogen. We obtained a sensor response time as short as 14 s at 1.4% hydrogen concentration with the 30-min pore-widening treatment of AAO template. The sensor exhibited very good performance at hydrogen concentrations from 0.1% to 2%. [ABSTRACT FROM AUTHOR]

Streptococcus suis serotype 2 ( S. suis 2) is a serious zoonotic pathogen causing septicemia and meningitis in piglets and humans. The capsular polysaccharide (CPS) is an essential virulence factor for S. suis 2 to infect the host. The synthesis of CPS repeating units involves multiple glycosyltransferases. In this study, four genes ( cps2E, cps2G, cps2J and cps2L ) encoding different glycosyltransferases involved in CPS synthesis were researched in S. suis 2. Four deletion mutants (Δ cps2E , Δ cps2G , Δ cps2J and Δ cps2L ) with their CPS incomplete and their sialic acid content significantly decreased were constructed in S. suis 2 SC19. All these four mutant strains showed enhanced adhesion to Hep-2 cells and increased sensitivity to phagocytosis. Flow cytometric analysis also revealed that these four mutants were more susceptible to the attack by the complement system. In a mouse model of infection, the mutant strains were rapidly cleared by the immune system, compared with the wild-type strain. In summary, this study characterized four genes ( cps2E , cps2G , cps2J and cps2L ) involved in CPS synthesis of S. suis 2 SC19 and it revealed that these genes were all crucial for SC19 to invade and survive in the host. [ABSTRACT FROM AUTHOR]

The persistent incidence of high levels of multidrug-resistant (MDR) bacteria seriously endangers global public health. In response to MDR-associated infections, new antibacterial drugs and strategies are particularly needed. Screening to evaluate a potential compound to reverse antibiotic resistance is a good strategy to alleviate this crisis. In this paper, using high-throughput screening methods, we identified that oxyclozanide potentiated tetracycline antibiotics act against MDR bacterial pathogens by promoting intracellular accumulation of tetracycline in resistant bacteria. Furthermore, mechanistic studies demonstrated that oxyclozanide could directly kill bacteria by disrupting bacterial membrane and inducing the overproduction of bacterial reactive oxygen species. Oxyclozanide effectively reduced the production of virulence proteins in S. aureus and neutralized the produced α-hemolysin, thereby effectively alleviating the inflammatory response caused by bacteria. Finally, oxyclozanide significantly reversed tetracycline resistance in animal infection assays. In summary, these results demonstrated the capacity of oxyclozanide as a novel antibiotic adjuvant, antibacterial and anti-virulence multifunctional compound to circumvent MDR bacteria and improve the therapeutic effect of persistent infections caused by MDR bacteria worldwide. [Display omitted] • The discovery of a novel type of antibacterial and anti-virulence multifunctional antibacterial agent. • Oxyclozanide remarkably potentiated the activity of tetracycline against MDR bacteria. • Oxyclozanide eliminated the activity of hemolysin and biofilm while inhibiting the production of MRSA toxins. • Oxyclozanide reversed tetracycline resistance against MDR bacteria in vivo. [ABSTRACT FROM AUTHOR]

In view of the urgent needs of current optical system for tunable focus and achromatism, this paper presents a one-dimensional tunable cylindrical liquid crystal lens based on FPGA controlled liquid crystal cell, which can realize tunable focus and achromatic function in time domain. Based on the indium tin oxide (ITO) one-dimensional stripe electrode structure, the lens can realize the self-focusing function through controlling the order and amplitude of external voltage applying on each unit electrode stripe. Experimentally, we designed 128 stripes electrode on the liquid crystal lens within 10 mm × 10 mm. The experimental result shows that the focal length varying range is from 300 mm to infinite in 633 nm. What's more, this liquid crystal lens has the ability to realize the transverse achromatic function to obtain the almost same focal point for both 405 nm and 633 nm incident beam by computer- electrically- controlled method within the time domain. The new type of electrically controlled element has the characteristics of high efficiency and small volume, which will hopefully play an important role in microscopic imaging and color display system in the future. [ABSTRACT FROM AUTHOR]

• Construction of miR-M7-5p deletion and revertant Marek's disease virus. • Deletion of miR-M7-5p does not affect growth of Marek's disease virus in cell culture. • Deletion of miR-M7-5p enhances replication of Marek's disease virus during early cytolytic phase. • Deletion of miR-M7-5p elevates pathogenicity of Marek's disease virus. MicroRNAs (miRNAs) are a class of ∼22 nucleotides non-coding RNAs that are encoded by a wide range of hosts. Viruses, especially herpesviruses, encode a variety of miRNAs that involved in disease progression. Recently, a cluster of virus-encoded miRNAs, miR-M8-M10, have been shown to restrict early cytolytic replication and pathogenesis of Marek's disease virus (MDV), an oncogenic avian alphaherpesvirus that causes lymphoproliferative disease in chickens. In this study, we specifically dissected the role of miR-M7, a member of cluster miR-M8-M10, in regulating MDV replication and pathogenesis. We found that deletion of miR-M7-5p did not affect the virus plaque size and growth in cell culture. However, compared to parental virus, infection of miR-M7-5p deletion virus significantly increased MDV genome copy number at 5 days post infection, suggesting that miR-M7 plays a role to restrict MDV replication during early cytolytic phase. In addition, our results showed that infection of miR-M7-5p deletion virus significantly enhanced the mortality of chickens, even it induced lymphoid organ atrophy similar to parental and revertant viruses. Taken together, our study revealed that the miR-M7 acts as a repressive factor of MDV replication and pathogenesis. [ABSTRACT FROM AUTHOR]

• E. coli PCN033 is more resistant to PMB than E. coli K12. • Treatment of E. coli with polymyxin B leads to induction of Rcs pathway. • We identified a regulator RcsB which specifically binds the promoter region in the T6SS gene cluster. • And we uncover a new model that Rcs system facilitate bacterial better survival under lethal attack. • Our findings broaden the important physiological functions of T6SS in adverse milieu. Signal transduction system and specialized secretory devices are crucial for bacteria to sense and adequately adapt in adverse environmental conditions. Therefore, it's crucial for microbes to detect and respond to lethal attacks when envelope is perturbed so as to minimize and fix the damage in milieu. We investigated the adaptive response of porcine extra-intestinal pathogenic Escherichia coli PCN033 to polymyxin B challenge. Treatment with polymyxin B led to rapid and robust activation of Rcs system via RcsF, as well as the accumulation of reactive oxygen species. ExPEC T6SS expression was strongly induced by RcsB in Rcs system, resulting in the reduction in the damage to constitute a survival strategy. Finally, we show that T6SS of ExPEC is involved in its pathogenicity in mouse model. Compared with the wild type strain, the deletion of T6SS genes led to a decrease in the organ colonization ability, and the RcsFS2DM3Q mutant that caused Rcs activation had a stronger colonization ability than the wild type strain. In conclusion, Rcs system orchestrates Rcs cascade to trigger antioxidant defense of T6SS, and presents a typical model in which a bacterium reschedule its transcription network via the Rcs phosphorelay pathway in response to membrane perturbations for survival and pathogenesis. [ABSTRACT FROM AUTHOR]