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1.
Pest Manag Sci ; 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32506667

RESUMO

BACKGROUND: Lymantria dispar is an economically impactful forest pest worldwide. The entomopathogenic fungi Beauveria bassiana shows great promise in pest management due to its high lethality in Lymantria dispar. A complete understanding of the immune interactions between the pest and the pathogenic fungus is essential to actualizing biological pest management. RESULTS: Following the infection of Lymantria dispar by Beauveria bassiana spores, we performed a time-course analysis of transcriptome in Lymantria dispar fat bodies and hemocytes to explore host immune response. A total of 244 immunity-related genes including pattern recognition receptors, extracellular signal modulators, immune pathways (Toll, IMD, JNK and JAK/STAT), and response effectors were identified. We observed contrasting tissue and time-specific differences in the expression of immune genes. At the early stage of infection, several recognition receptors and effector genes were activated, while the signal modulation and effector genes were suppressed at later stages. Further enzyme activity-based assays coupled with gene expression analysis of prophenoloxidase revealed a significant upregulation of phenoloxidase activity at 48- and 72-h post-infection. Moreover, fungal infection led to dysbiosis in gut microbiota that seems to be partially attributed to reduced gut hydrogen peroxide (H2 O2 ) amount, which indicates a significant impact of fungal infection on host gut microbes. CONCLUSION: Our study provides a comprehensive sequence resource and crucial new insights about an economically important forest pest. Specifically, we elucidate the complicated multipartite interaction between host and fungal pathogen and contribute to a better understanding of Lymantria dispar anti-fungal immunity, resulting in better tools for biological pest control.

2.
ACS Appl Mater Interfaces ; 12(23): 26432-26443, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32429664

RESUMO

The development of a highly effective photosensitizer (PS) that can be activated with a low-power single light is a pressing issue. Herein, we report a PS for synergistic photodynamic and photothermal therapy constructed through self-assembly of poly(selenoviologen) on the surface of core-shell NaYF4:Yb/Tm@NaYF4 upconversion nanoparticles. The hybrid UCNPs/PSeV PS showed strong ROS generation ability and high photothermal conversion efficiency (∼52.5%) under the mildest reported-to-date irradiation conditions (λ = 980 nm, 150 mW/cm2, 4 min), leading to a high efficiency in killing methicillin-resistant Staphylococcus aureus (MRSA) both in vitro and in vivo. Remarkably, after intravenous injection, the reported PS accumulated preferentially in deep MRSA-infected tissues and achieved an excellent therapeutic index. This PS design realizes a low-power single-NIR light-triggered synergistic phototherapy and provides a simple and versatile strategy to develop safe clinically translatable agents for efficient treatment of deep tissue bacterial inflammations.

3.
ACS Appl Mater Interfaces ; 12(16): 18385-18394, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32212618

RESUMO

The development of novel applications of ultralong organic phosphorescent (UOP) materials is highly desired. Herein, a series of UOP materials (EDCz, E = O, S, Se, and Te) for bacterial afterglow imaging and photodynamic therapy (PDT) is reported. By structurally bonding with the chalcogen atoms with π-conjugated scaffolds, EDCz not only absorbs visible light but also emits UOP with an efficiency of ca. 0.01-6.8% and a long lifetime of 0.08-0.318 s under ambient conditions. Benefiting from the long-lived triplet excited states, the SeDCz nanocrystals (NCs) possessed the best optical properties in the series, generating 1O2 under white light irradiation and performing as an agent for Staphylococcus aureus afterglow imaging and PDT at a low concentration (98 ng mL-1). The SeDCz NCs are also utilized as real-time UOP imaging agents and promoted healing of infected wounds in living mice. To the best of our knowledge, this study presents the first example of UOP-based bacterial photodynamic theranostic agents and creates a platform for the next-generation efficient UOP-based photosensitizers for bioimaging and skin regeneration.

4.
J Exp Bot ; 71(9): 2670-2677, 2020 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31903493

RESUMO

Transplastomic potato plants expressing double-stranded RNA (dsRNA) targeted against essential genes of the Colorado potato beetle (CPB) can be lethal to larvae by triggering an RNA interference (RNAi) response. High accumulation levels of dsRNAs in plastids are crucial to confer an efficient RNAi response in the insects. However, whether length and sequence of the dsRNA determine the efficacy of RNAi and/or influence the level of dsRNA accumulation in plastids is not known. We compared the RNAi efficacy of different lengths of dsRNA targeted against the CPB ß-Actin gene (ACT) by feeding in vitro-synthesized dsRNAs to larvae. We showed that, while the 60 bp dsRNA induced only a relatively low RNAi response in CPB, dsRNAs of 200 bp and longer caused high mortality and similar larval growth retardation. When the dsRNAs were expressed from the plastid (chloroplast) genome of potato plants, we found that their accumulation were negatively correlated with length. The level of dsRNA accumulation was positively associated with the observed mortality, suppression of larval growth, and suppression of target gene expression. Importantly, transplastomic potato plants expressing the 200 bp dsRNA were better protected from CPB than plants expressing the 297 bp dsRNA, the best-performing line in our previous study. Our results suggest that the length of dsRNAs is an important factor that influences their accumulation in plastids and thus determines the strength of the insecticidal RNAi effect. Our findings will aid the design of optimized dsRNA expression constructs for plant protection by plastid-mediated RNAi.

5.
J Am Chem Soc ; 142(5): 2592-2600, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31940435

RESUMO

It is quite challenging to realize fluorescence resonance energy transfer (FRET) between two chromophores with specific positions and directions. Herein, through the self-assembly of two carefully selected fluorescent ligands via metal-coordination interactions, we prepared two tetragonal prismatic platinum(II) cages with a reverse FRET process between their faces and pillars. Bearing different responses to external stimuli, these two emissive ligands are able to tune the FRET process, thus making the cages sensitive to solvents, pressure, and temperature. First, these cages could distinguish structurally similar alcohols such as n-butanol, t-butanol, and i-butanol. Furthermore, they showed decreased emission with bathochromic shifts under high pressure. Finally, they exhibited a remarkable ratiometric response to temperature over a wide range (223-353 K) with high sensitivity. For example, by plotting the ratio of the maximum emission (I600/I480) of metallacage 4b against the temperature, the slope reaches 0.072, which is among the highest values for ratiometric fluorescent thermometers reported so far. This work not only offers a strategy to manipulate the FRET efficiency in emissive supramolecular coordination complexes but also paves the way for the future design and preparation of smart emissive materials with external stimuli responsiveness.

6.
J Econ Entomol ; 113(1): 451-460, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-31773146

RESUMO

Apolygus lucorum (Meyer-Dür) is a destructive pest to >280 plants. Major economic significance and pesticide resistance issues have created a need for integrated pest management (e.g., RNAi, entomopathogen-based bioinsecticides) for A. lucorum. To better develop these control strategies, large-scale genetic studies involving gene-expression analysis are required and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the most commonly used method. However, there have been no reports on appropriate reference genes in A. lucorum. Here, we evaluated nine widely utilized reference genes including EF1γ, RPL32, RPL27, SDH, TBP, ACT, ACT2, GAPDH, and ßTUB for their expression stabilities in A. lucorum under five different conditions i.e., life stage, tissue, sex, dsRNA injection, and entomopathogen infection. Based on the gene stability ranking calculated by RefFinder, which integrates four algorithms (geNorm, delta Ct method, NormFinder, and BestKeeper), we recommend RPL27 and RPL32 as the most appropriate reference genes for molecular studies in different life stages and tissues; GAPDH and EF1γ for different sexes and entomopathogen infection studies; and RPL27 and EF1γ for RNAi studies. The results of this study will help improve the accuracy and reliability for normalizing the RT-qPCR data for further molecular analysis in A. lucorum.

7.
Insects ; 10(12)2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31766384

RESUMO

RNA interference (RNAi) has emerged as a novel and feasible strategy for pest management. Methods for cost-effective production and stable delivery of double-stranded RNA (dsRNA) to the target insects are crucial for the wide application of RNAi for pest control. In this study, we tested the expression of dsRNA in RNaseIII-deficient Escherichia coli HT115 which was then fed to Plagiodera versicolora larvae, an insect pest of Salicaceae plants worldwide. By targeting six potential genes, including actin (ACT), signal recognition particle protein 54k (SRP54), heat shock protein 70 (HSC70), shibire (SHI), cactus (CACT), and soluble N-ethylmaleimide-sensitive fusion attachment proteins (SNAP), we found that feeding bacteria-expressed dsRNA successfully triggered the silencing of the five target genes tested and the suppression of ACT and SRP54 genes caused significant mortality. Our results suggest that the oral delivery of bacteria-expressed dsRNA is a potential alternative for the control of P. versicolora, and that ACT and SRP54 genes are the potent targets.

8.
Org Lett ; 21(20): 8285-8289, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31553197

RESUMO

A series of chalcogen-containing carborane derivatives were synthesized through a one-pot reaction. The nonconjugated six-membered ring of carborane-fused disulfide (1) can be electrochemically reduced to a dithiolate derivative. The five-membered ring of carborane-fused chalcogenophenes (2-4) showed aromaticity and considerable σ-π conjugation. The dicarborane chalcogenides (5-7) showed intramolecular charge-transfer-induced emission. These chalcogen-containing carborane derivatives provided a useful platform to study the electron interaction systematically and shed some light on the design of carborane-based optoelectronic materials.

9.
Inorg Chem ; 58(19): 13323-13336, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31503465

RESUMO

A modular route to previously inaccessible classes of ring-fused π-extended heteroacenes bearing the heavy inorganic element tellurium (Te) is presented. These new materials can be viewed as n-doped analogs of molecular graphene subunits that exhibit color tunable visible light phosphorescence in the solid state and in the presence of air. The general mechanism of phosphorescence in these systems was probed experimentally and computationally via time-dependent density functional theory (TD-DFT). The incorporation of Te into π-extended oligoacene frameworks was achieved by an efficient Zr/Te transmetalation protocol; related zirconium-element exchange reactions have been used to prepare both electron-rich and electron-deficient heterocycles containing different elements from throughout the p-block. Therefore, the current study provides a clear path to incorporate inorganic elements into heteroacenes of greater complexity and side group selectivity compared to existing synthetic routes.

10.
Chemistry ; 25(59): 13472-13478, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31393035

RESUMO

A series of water-soluble cationic chalcogenoviologen-based photosensitizers for photodynamic antimicrobial therapy (PDAT) is reported. The Se-containing derivatives (SeMV2+ ) 5 b and 6 b showed good antimicrobial activities due to the presence of chalcogen atoms and a cationic scaffold. The former efficiently enhanced the generation of reactive oxygen species (ROS), and the latter facilitated the ROS delivery to bacteria, resulting in their death. Interestingly, alkyl-modified photosensitizers showed higher antimicrobial activities than commonly reported photosensitizers with quaternary ammonium (QA) groups. In particular, the SeMV2+ (6 b) with excellent antibacterial activities efficiently promoted the healing of infected wounds in mice. Simple yet novel, nontoxic and biocompatible chalcogenoviologens provided a promising strategy to develop new efficient photosensitizers for photodynamic antimicrobial therapy and skin regeneration.


Assuntos
Anti-Infecciosos/química , Cátions/química , Fármacos Fotossensibilizantes/uso terapêutico , Espécies Reativas de Oxigênio/química , Pele/fisiopatologia , Animais , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Camundongos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Regeneração
11.
Insects ; 10(8)2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31416137

RESUMO

Dendroctonus valens, an invasive bark beetle, has caused severe damage to Chinese forests. Previous studies have highlighted the importance of the gut microbiota and its fundamental role in host fitness. Culture-dependent and culture-independent methods have been applied in analyzing beetles' gut microbiota. The former method cannot present a whole picture of the community, and the latter mostly generates short read lengths that cannot be assigned to species. Here, the PacBio sequencing system was utilized to capture full-length 16S rRNA sequences in D. valens gut throughout its ontogeny. A total of eight phyla, 55 families, 102 genera, and 253 species were identified. Bacterial communities in colonized beetles have the greatest richness but the lowest evenness in all life stages, which is different from those in young larvae. Pseudomonas sp., Serratia liquefaciens possess high abundance throughout its ontogeny and may serve as members of the core bacteriome. A phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis predicted that gut microbiota in larvae are rich in genes involved in carbohydrate, energy metabolism. Gut microbiota in both larvae and colonized beetles are rich in xenobiotics and terpenoids biodegradation, which are decreased in dispersal beetles. Considering that the results are based mainly on the analysis of 16S rRNA sequencing and PICRUSt prediction, further confirmation is needed to improve the knowledge of the gut microbiota in D. valens and help to resolve taxonomic uncertainty at the species level.

12.
Tree Physiol ; 39(9): 1525-1532, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31222266

RESUMO

Plastid transformation technology has several attractive features compared with traditional nuclear transformation technology. However, only a handful of species are able to be successfully transformed. Here, we report an efficient and stable plastid transformation protocol for poplar, an economically important tree species grown worldwide. We transformed the Bacillus thuringiensis cry1C gene into the poplar plastid genome, and homoplasmic transplastomic poplar was obtained after two to three rounds of regeneration under antibiotic selection for 7-12 months. The transplastomic poplar expressing Cry1C insecticidal protein showed the highest accumulation level in young leaves, which reached up to 20.7 µg g-1 fresh weight, and comparatively low levels in mature and old leaves, and hardly detectable levels in non-green tissues, such as phloem, xylem and roots. Transplastomic poplar showed high toxicity to Hyphantria cunea and Lymantria dispar, two notorious forest pests worldwide, without affecting plant growth. These results are the first successful examples of insect-resistant poplar generation by plastid genome engineering and provide a new avenue for future genetic improvement of poplar plants.


Assuntos
Bacillus thuringiensis , Genomas de Plastídeos , Populus , Animais , Larva , Folhas de Planta , Plantas Geneticamente Modificadas
13.
Angew Chem Int Ed Engl ; 58(25): 8468-8473, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-30951238

RESUMO

A series of electrochromic electron-accepting poly(chalcogenoviologen)s with multiple, stable, and reversible redox centers were used as anodic materials in organic radical lithium-ion batteries (ORLIBs). The introduction of heavy atoms (S, Se, and Te) into the viologen scaffold significantly improved the capacity and cycling stability of the ORLIBs. Notably, the poly(Te-BnV) anode was able to intercalate 20 Li ions and showed higher conductivity and insolubility in the electrolyte, thus contributing to a reversible capacity of 502 mAh g-1 at 100 mA g-1 when the Coulombic efficiency approached 100 %. The charged/discharged state of flexible electrochromic batteries fabricated from these anodic materials could be monitored visually owing to the unique electrochromic and redox properties of the materials. This study opens a promising avenue for the development of organic polymer-based electrodes for flexible hybrid visual electronics.

14.
Chemistry ; 25(36): 8479-8483, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31034114

RESUMO

Guest-controlled diastereoselective self-assembly of a diboryltellurophene and a chiral tetrol bearing an indacene backbone was achieved to give either hetero- or homochiral macrocyclic boronic esters, selectively. The heterochiral isomer (hetero-[2+2]Te ) exhibited a higher inclusion ability for electron-deficient aromatic guests, leading to effective quenching of phosphorescence from the diboryltellurophene moieties. The reported macrocycles collectively represent a promising arene sensing approach based on phosphorescence.

16.
Pest Manag Sci ; 75(1): 170-179, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29797399

RESUMO

BACKGROUND: Insects form both mutualistic and antagonistic relationships with microbes, and some antagonistic microbes have been used as biocontrol agents (BCAs) in pest management. Contextually, BCAs may be inhibited by beneficial insect symbionts, which can become potential barriers to entomopathogen-dependent pest biocontrol. Using the symbioses formed by one devastating dipteran pest, Delia antiqua, and its associated microbes as a model system, we sought to determine whether the antagonistic interaction between BCAs and microbial symbionts could affect the outcome of entomopathogen-dependent pest biocontrol. RESULTS: The result showed that in contrast to non-axenic D. antiqua larvae, i.e., onion maggots, axenic larvae lost resistance to the entomopathogenic Beauveria bassiana, and the re-inoculation of microbiota increased the resistance of axenic larvae to B. bassiana. Furthermore, bacteria frequently isolated from larvae, including Citrobacter freundii, Enterobacter ludwigii, Pseudomonas protegens, Serratia plymuthica, Sphingobacterium faecium and Stenotrophomonas maltophilia, suppressed B. bassiana conidia germination and hyphal growth, and the re-inoculation of specific individual bacteria enhanced the resistance of axenic larvae to B. bassiana. CONCLUSION: Bacteria associated with larvae, including C. freundii, E. ludwigii, P. protegens, S. plymuthica, S. faecium and S. maltophilia, can inhibit B. bassiana infection. Removing the microbiota can suppress larval resistance to fungal infection. © 2018 Society of Chemical Industry.


Assuntos
Beauveria/fisiologia , Dípteros/microbiologia , Microbiota , Controle Biológico de Vetores , Animais , China , Dípteros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/microbiologia
17.
Org Lett ; 21(1): 109-113, 2019 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-30560667

RESUMO

The selective construction of various dibora[10]annulenes through mild boron-tin exchange reactions is reported. Dibora[10]annulenes exhibit optical and electrochemical properties of value for future sensing applications. Controlled addition of the Lewis base pyridine to dibora[10]annulenes instigates a selective ring-opening reaction. This work explores a new area of boron chemistry that represents the first step in the potential formation of dibora[10]annulene-derived polymers.

18.
ACS Appl Mater Interfaces ; 10(41): 35469-35476, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30252431

RESUMO

Organic carboxyl compounds are promising anode candidates for lithium ion batteries in which oxygen-related redox dominates the reaction mechanisms. Herein, two nanostructured organic electrodes of π-extended naphthyl-based dicarboxylate and dithiocarboxylate compounds, namely sodium naphthalene-2,6-dicarboxylate (SND) and sodium naphthalene-2,6-bis(carbothioate) (SNB) are first synthesized and investigated systematically for lithium ion battery. Through introducing less electronegative sulfur atoms into carboxylic groups at molecular level, SNB exhibits a different voltage profile and delivers higher reversible capacity of 280 mAh g-1 than SND (198 mAh g-1) at a current density of 50 mA g-1. A combination of electrochemical properties and DFT calculations reveals that SNB could reversibly store three Li+ per formula unit, while SND only stores two Li+. The present work offers a new strategy to develop redox molecules with tunable redox potentials and accommodation more alkaline ions for high performance battery systems.

19.
Angew Chem Int Ed Engl ; 57(45): 14841-14846, 2018 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-30239084

RESUMO

The synthesis of the first bismuth-containing macromolecules that exhibit phosphorescence in the solid state and in the presence of oxygen is reported. These red emissive high molecular weight polymers (>300 kDa) feature benzobismoles appended to a hydrocarbon scaffold, and were built via an efficient ring-opening metathesis (ROMP) protocol. Moreover, our general procedure readily allows for the formation of cross-linked networks and block copolymers. Attaining stable red phosphorescence with non-toxic elements remains a challenge and, thus, our new class of soluble (processable) polymeric phosphor is of great interest. Furthermore, the formation of bismuth-rich cores within organic-inorganic block copolymer spherical micelles is possible, leading to patterned arrays of bismuth in the film state.

20.
Chem Commun (Camb) ; 54(66): 9226-9229, 2018 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30065983

RESUMO

A series of novel persistent room-temperature phosphorescence (pRTP) materials (PEPCz) obtained via a combination of chalcogen atoms (O, S, Se, and Te) and a carbazolyl moiety is reported. Single crystal structure analysis revealed that PEPCz had similar molecular conformations and almost identical crystal packing. Mechanistic study showed that the intramolecular electronic coupling between the chalcogen atoms and π-units was responsible for tunable pRTP. The PEPCz were used not only to realize graphic encryption, but also to fabricate pRTP sensors for H2O2 and TNT detection.


Assuntos
Carbazóis/química , Calcogênios/química , Substâncias Luminescentes/química , Carbazóis/síntese química , Calcogênios/síntese química , Peróxido de Hidrogênio/análise , Luminescência , Substâncias Luminescentes/síntese química , Modelos Químicos , Teoria Quântica , Temperatura , Trinitrotolueno/análise
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