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1.
Arch Virol ; 166(10): 2881-2885, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34338875

RESUMO

Here, we describe a novel mycovirus, tentatively designated as "Botryosphaeria dothidea mitovirus 3" (BdMV3), isolated from Botryosphaeria dothidea strain FJ, which causes pear ring rot disease in Fujian Province, China. The complete genome nucleotide sequence of BdMV3 is 2538 nt in length and contains a single 2070-nt open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) of 689 amino acids (aa) using the fungal mitochondrial genetic code. BLASTp analysis revealed that the RdRp of BdMV3 shares 28.91%-69.36% sequence identity (query sequence coverage more than 90%) with those of members of the genus Mitovirus, with the highest sequence identity of 69.36% and 68.79% to the corresponding RdRp aa sequences of Rhizoctonia solani mitovirus 10 and Macrophomina phaseolina mitovirus 4, respectively. Phylogenetic analysis based on RdRp aa sequences indicated that BdMV3 is a new member of the genus Mitovirus in the family Mitoviridae.


Assuntos
Ascomicetos/virologia , Genoma Viral/genética , Doenças das Plantas/microbiologia , Pyrus/microbiologia , Vírus de RNA/genética , Sequência de Aminoácidos , China , Micovírus/classificação , Micovírus/genética , Fases de Leitura Aberta/genética , Filogenia , Vírus de RNA/classificação , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética
2.
Small ; 16(20): e2000852, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32323489

RESUMO

Tuning bandgap and phases in the ternary 2D transition metal dichalcogenides (TMDs) alloys has opened up unexpected opportunities to engineer optoelectronic properties and explore potential applications. In this work, a salt-assisted chemical deposition vapor (CVD) growth strategy is reported for the creation of high-quality monolayer W1- x Rex S2 alloys to fulfill a readily phase control from 1H to DT by changing the ratio of Re and W precursors. The structures and chemical compositions of doping alloys are confirmed by combining atomic resolution scanning transmission electron microscopy-annular dark field imaging with energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy, matching well with the calculated results. The field-effect transistors (FETs) devices fabricated based on 1H-W0.9 Re0.1 S2 monolayer exhibit a n-type semiconducting behavior with the mobility of 0.4 cm2 V-1 s-1 . More importantly, the FETs show high-performance responsivity with a value of 17 µA W-1 in air, which is superior to that of monolayer CVD-grown WS2 . This work paves the way toward synthesizing monolayer ternary alloys with controlled phases for potential optoelectronic applications.

3.
Nano Lett ; 20(5): 3872-3879, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32293186

RESUMO

GeSn offers a reduced bandgap than Ge and has been utilized in Si-based infrared photodetectors with an extended cutoff wavelength. However, the traditional GeSn/Ge heterostructure usually consists of defects like misfit dislocations due to the lattice mismatch issue. The defects with the large feature size of a photodetector fabricated on bulk GeSn/Ge heterostructures induce a considerable dark current. Here, we demonstrate a flexible GeSn/Ge dual-nanowire (NW) structure, in which the strain relaxation is achieved by the elastic deformation without introducing defects, and the feature dimension is naturally at the nanoscale. A photodetector with a low dark current can be built on a GeSn/Ge dual-NW, which exhibits an extended detection wavelength beyond 2 µm and enhanced responsivity compared to the Ge NW. Moreover, the dark current can be further suppressed by the depletion effect from the ferroelectric polymer side gate. Our work suggests the flexible GeSn/Ge dual-NW may open an avenue for Si-compatible optoelectronic circuits operating in the short-wavelength infrared range.

4.
IMA Fungus ; 10: 3, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32647612

RESUMO

Pear ring rot disease, mainly caused by Botryosphaeria dothidea, is widespread in most pear and apple-growing regions. Mycoviruses are used for biocontrol, especially in fruit tree disease. BdCV1 (Botryosphaeria dothidea chrysovirus 1) and BdPV1 (Botryosphaeria dothidea partitivirus 1) influence the biological characteristics of B. dothidea strains. BdCV1 is a potential candidate for the control of fungal disease. Therefore, it is vital to explore interactions between B. dothidea and mycovirus to clarify the pathogenic mechanisms of B. dothidea and hypovirulence of B. dothidea in pear. A high-quality full-length genome sequence of the B. dothidea LW-Hubei isolate was obtained using Single Molecule Real-Time sequencing. It has high repeat sequence with 9.3% and DNA methylation existence in the genome. The 46.34 Mb genomes contained 14,091 predicted genes, which of 13,135 were annotated. B. dothidea was predicted to express 3833 secreted proteins. In bioinformatics analysis, 351 CAZy members, 552 transporters, 128 kinases, and 1096 proteins associated with plant-host interaction (PHI) were identified. RNA-silencing components including two endoribonuclease Dicer, four argonaute (Ago) and three RNA-dependent RNA polymerase (RdRp) molecules were identified and expressed in response to mycovirus infection. Horizontal transfer of the LW-C and LW-P strains indicated that BdCV1 induced host gene silencing in LW-C to suppress BdPV1 transmission. To investigate the role of RNA-silencing in B. dothidea defense, we constructed four small RNA libraries and sequenced B. dothidea micro-like RNAs (Bd-milRNAs) produced in response to BdCV1 and BdPV1 infection. Among these, 167 conserved and 68 candidate novel Bd-milRNAs were identified, of which 161 conserved and 20 novel Bd-milRNA were differentially expressed. WEGO analysis revealed involvement of the differentially expressed Bd-milRNA-targeted genes in metabolic process, catalytic activity, cell process and response to stress or stimulus. BdCV1 had a greater effect on the phenotype, virulence, conidiomata, vertical and horizontal transmission ability, and mycelia cellular structure biological characteristics of B. dothidea strains than BdPV1 and virus-free strains. The results obtained in this study indicate that mycovirus regulates biological processes in B. dothidea through the combined interaction of antiviral defense mediated by RNA-silencing and milRNA-mediated regulation of target gene mRNA expression.

5.
Nanotechnology ; 30(7): 074004, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30523993

RESUMO

We report a NO2 gas sensor based on germanium quantum dots (GeQDs)/graphene hybrids. Graphene was directly grown on germanium through chemical vapor deposition and the GeQDs were synthesized via molecular beam epitaxy. The samples were characterized by atomic force microscope, Raman spectra, scanning electron microscope, x-ray photoelectron spectroscope and transmission electron microscope with energy dispersive x-ray. By introducing GeQDs on graphene, the gas sensor sensitivity to NO2 was improved substantially. With the optimization of the growth time of GeQDs (600 s), the response sensitivity to 10 ppm NO2 can be as high as 3.88, which is 20 times higher than that of the graphene sensor without GeQDs decoration. In addition, the 600 s GeQDs/graphene hybrid sensor exhibits fast response and recovery rates as well as excellent stability. Our work may provide a new route to produce low-power consumption, portable, and room temperature gas sensor which is amenable to mass production.

6.
Virol J ; 15(1): 126, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-30103770

RESUMO

BACKGROUND: Pear ring rot, caused by Botryosphaeria species, is responsible for substantial economic losses by causing severe recession of pear tree growth in China. Mycovirus-mediated hypovirulence in plant pathogenic fungi is a crucial biological method to control fungal diseases. METHODS: We conducted a large-scale and comprehensive transcriptome analysis to identify mRNA in B. dothidea in response to mycovirus. De novo sequencing technology from four constructed libraries of LW-C (Botryosphaeria dothidea chrysovirus 1, BdCV1), LW-P (Botryosphaeria dothidea partitivirus 1, BdPV1), LW-CP (LW-1 strain infection with BdCV1 and BdPV1), and Mock (free virus) was used to investigate and compare gene expression changes in B.dothidea strains infected with mycovirus. RESULTS: In total, 30,058 Unigenes with an average length of 2128 bp were obtained from 4 libraries of B. dothidea strains. These were annotated to specify their classified function. We demonstrate that mRNAs of B. dothidea strains in response to mycovirus are differentially expressed. In total, 5598 genes were up-regulated and 3298 were down-regulated in the LW-CP group, 4468 were up-regulated and 4291 down-regulated in the LW-C group, and 2590 were up-regulated and 2325 down-regulated in the LW-P group. RT-qPCR was used to validate the expression of 9 selected genes. The B. dothidea transcriptome was more affected by BdCV1 infection than BdPV1. We conducted GO enrichment analysis to characterize gene functions regulated by B. dothidea with mycovirus infection. These involved metabolic process, cellular process, catalytic activity, transporter activity, signaling, and other biological pathways. KEGG function analysis demonstrated that the enriched differentially expressed genes are involved in metabolism, transcription, signal transduction, and ABC transport. mRNA is therefore involved in the interaction between fungi and mycovirus. In addition, changes in differential accumulation levels of cp and RdRp of BdCV1 and BdPV1 in B. dothidea strains were evaluated, revealing that the accumulation of BdCV1 and BdPV1 is related to the phenotype and virulence of B. dothidea strain LW-1. CONCLUSIONS: The identification and analysis of mRNAs from B. dothidea was first reported at the transcriptome level. Our analysis provides further insight into the interaction of B. dothidea strains infection with chrysovirus 1 (BdCV1) and partitivirus 1 (BdPV1) at the transcriptome level.


Assuntos
Ascomicetos/genética , Ascomicetos/virologia , Perfilação da Expressão Gênica , Doenças das Plantas/microbiologia , Doenças das Plantas/virologia , Pyrus/microbiologia , Ascomicetos/patogenicidade , Proteínas Fúngicas/genética , Micovírus/genética , Regulação Fúngica da Expressão Gênica , Redes e Vias Metabólicas , RNA Mensageiro/genética , Proteínas Virais/genética , Virulência/genética
7.
Virol J ; 13(1): 166, 2016 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-27716257

RESUMO

BACKGROUND: Heat treatment (known as thermotherapy) together with in vitro culture of shoot meristem tips is a commonly used technology to obtain virus-free germplasm for the effective control of virus diseases in fruit trees. RNA silencing as an antiviral defense mechanism has been implicated in this process. To understand if high temperature-mediated acceleration of the host antiviral gene silencing system in the meristem tip facilitates virus-derived small interfering RNAs (vsiRNA) accumulation to reduce the viral RNA titer in the fruit tree meristem tip cells, we used the Apple stem grooving virus (ASGV)-Pyrus pyrifolia pathosystem to explore the possible roles of vsiRNA in thermotherapy. RESULTS: At first we determined the full-length genome sequence of the ASGV-Js2 isolate and then profiled vsiRNAs in the meristem tip of in vitro-grown pear (cv. 'Jinshui no. 2') shoots infected by ASGV-Js2 and cultured at 24 and 37 °C. A total of 7,495 and 7,949 small RNA reads were obtained from the tips of pear shoots cultured at 24 and 37 °C, respectively. Mapping of the vsiRNAs to the ASGV-Js2 genome revealed that they were unevenly distributed along the ASGV-Js2 genome, and that 21- and 22-nt vsiRNAs preferentially accumulated at both temperatures. The 5'-terminal nucleotides of ASGV-specific siRNAs in the tips cultured under different temperatures had a similar distribution pattern, and the nucleotide U was the most frequent. RT-qPCR analyses suggested that viral genome accumulation was drastically compromised at 37 °C compared to 24 °C, which was accompanied with the elevated levels of vsiRNAs at 37 °C. As plant Dicer-like proteins (DCLs), Argonaute proteins (AGOs), and RNA-dependent RNA polymerases (RDRs) are implicated in vsiRNA biogenesis, we also cloned the partial sequences of PpDCL2,4, PpAGO1,2,4 and PpRDR1 genes, and found their expression levels were up-regulated in the ASGV-infected pear shoots at 37 °C. CONCLUSIONS: Collectively, these results showed that upon high temperature treatment, the ASGV-infected meristem shoot tips up-regulated the expression of key genes in the RNA silencing pathway, induced the biogenesis of vsiRNAs and inhibited viral RNA accumulation. This study represents the first report on the characterization of the vsiRNA population in pear plants infected by ASGV-Js2, in response to high temperature treatment.


Assuntos
Flexiviridae/crescimento & desenvolvimento , Temperatura Alta , Brotos de Planta/virologia , Pyrus/virologia , RNA Interferente Pequeno/genética , Flexiviridae/genética , Flexiviridae/efeitos da radiação , Inativação Gênica , Brotos de Planta/imunologia , Brotos de Planta/efeitos da radiação , Pyrus/imunologia , Pyrus/efeitos da radiação , RNA Interferente Pequeno/metabolismo , RNA Viral/antagonistas & inibidores
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