Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Environ Technol ; : 1-10, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38312076

RESUMO

A series of activated carbon was obtained from rape straw by chemical modification with phosphoric acid (H3PO4). The activated carbon was characterized and the adsorption capacity for Rhodamine B (RhB) from water was analysed. The SEM images showed that PRC-40 is a porous material and the BET analysis revealed a high surface area of 1720 m2/g with the coexistence of micropores and mesopores. The FTIR spectra determined the presence of oxygenated functional groups at its surface. The XPS spectra revealed that the content of carboxyl and metaphosphate groups in the modified activated carbon significantly increased, and this is conducive to the adsorption reaction. The XRD pattern showed the amorphous nature of carbon. The effect of significant parameters, such as the concentration of H3PO4 for modification and pH value, has been discussed. The kinetic data showed that the pseudo-second-order model is predominant. Besides, the Langmuir model was compatible well with the equilibrium data, and the maximum adsorption capacity of the activated carbon modified by H3PO4 was 2882.84 mg/g. Therefore, agricultural waste and rape straw can be used to prepare effective adsorbents for the application with the removal of dye from wastewater.

2.
Arch Virol ; 169(1): 13, 2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38155262

RESUMO

A novel negative-stranded RNA mycovirus was isolated from the phytopathogenic fungus Fusarium sibiricum strain AH32. This virus, tentatively named "Fusarium sibiricum coguvirus 1" (FsCV1), has a bipartite genome consisting of two RNA segments (RNA1 and RNA2). The negative-sense RNA1 is 6711 nt in length, encoding the RNA-dependent RNA polymerase (RdRp, p251) in the viral complementary (vc) strand. The ambisense RNA2 (1204 nt long) encodes two proteins from overlapping genes: the nucleocapsid protein (NP, p38) in the vc strand and a protein of unknown function (UFP, p36) in the viral (v) strand. In contrast to other Bunyavirales members, in FsCV1, the two open reading frames are separated by a long AU-rich intergenic region (IR). Sequence comparisons and phylogenetic analysis based on RdRp and NP sequences demonstrated that FsCV1 is a novel bipartite negative-stranded RNA mycovirus of the genus Coguvirus, family Phenuiviridae, order Bunyavirales.


Assuntos
Micovírus , Fusarium , Vírus de RNA , Filogenia , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , RNA de Cadeia Dupla/genética , Fases de Leitura Aberta , Genoma Viral
3.
Adv Sci (Weinh) ; 10(29): e2302606, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37587761

RESUMO

Mycovirus-mediated hypovirulence has the potential to control fungal diseases. However, the availability of hypovirulence-conferring mycoviruses for plant fungal disease control is limited as most fungal viruses are asymptomatic. In this study, the virus-induced gene silencing (VIGS) vector p26-D4 of Fusarium graminearum gemytripvirus 1 (FgGMTV1), a tripartite circular single-stranded DNA mycovirus, is successfully constructed to convert the causal fungus of cereal Fusarium head blight (FHB) into a hypovirulent strain. p26-D4, with an insert of a 75-150 bp fragment of the target reporter transgene transcript in both sense and antisense orientations, efficiently triggered gene silencing in Fusarium graminearum. Notably, the two hypovirulent strains, p26-D4-Tri101, and p26-D4-FgPP1, obtained by silencing the virulence-related genes Tri101 and FgPP1 with p26-D4, can be used as biocontrol agents to protect wheat from a fungal disease FHB and mycotoxin contamination at the field level. This study not only describes the first mycovirus-derived VIGS system but also proves that the VIGS vector can be used to establish multiple hypovirulent strains to control pathogenic fungi.


Assuntos
Micovírus , Fusarium , Micoses , Fusarium/genética , Micovírus/genética , Triticum/genética , Triticum/microbiologia , Plantas
4.
J Fungi (Basel) ; 10(1)2023 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-38248920

RESUMO

Fungal endophytes are well-known for their ability to promote plant growth and hinder fungal diseases, including Fusarium head blight (FHB) caused by Fusarium graminearum. This study aimed to characterize the biocontrol efficacy of strain J4-3 isolated from the stem of symptomless wheat collected from Heilongjiang Province, China. It was identified as Epicoccum layuense using morphological characteristics and phylogenetic analysis of the rDNA internal transcribed spacer (ITS) and beta-tubulin (TUB). In a dual culture assay, strain J4-3 significantly inhibited the mycelial growth of F. graminearum strain PH-1 and other fungal pathogens. In addition, wheat coleoptile tests showed that lesion symptoms caused by F. graminearum were significantly reduced in wheat seedlings treated with hyphal fragment suspensions of strain J4-3 compared to the controls. Under field conditions, applying spore suspensions and culture filtrates of strain J4-3 with conidial suspensions of F. graminearum on wheat spikes resulted in the significant biocontrol efficacy of FHB. In addition, wheat seedlings previously treated with spore suspensions of strain J4-3 before sowing successfully resulted in FHB reduction after the application of conidial suspensions of F. graminearum at anthesis. More importantly, wheat seedlings treated with hyphal fragments and spore suspensions of strain J4-3 showed significant increases in wheat growth compared to the controls under greenhouse and field conditions. Overall, these findings suggest that E. layuense J4-3 could be a promising biocontrol agent (BCA) against F. graminearum, causing FHB and a growth-promoting fungus in wheat.

5.
J Fungi (Basel) ; 8(12)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36547570

RESUMO

Small RNA (sRNA) plays a central role in RNA silencing in fungi. The genome of Fusarium graminearum gemytripvirus 1 (FgGMTV1) is comprised of three DNA segments: DNA-A, DNA-B, and DNA-C. DNA-A and DNA-B are associated with fungal growth and virulence reduction. To elucidate the role of RNA silencing during the interactions of fungi and viruses, the sRNA profiles of F. graminearum in association with FgGMTV1 were established, using an FgGMTV1-free library (S-S), a library for infection with the DNA-A and DNA-B segments (S-AB), and a library for infection with the DNA-A, DNA-B, and DNA-C segments (S-ABC). A large amount of virus-derived sRNA (vsiRNA) was detected in the S-AB and S-ABC libraries, accounting for 9.9% and 13.8% of the total sRNA, respectively, indicating that FgGMTV1 triggers host RNA silencing. The total numbers of sRNA reads differed among the three libraries, suggesting that FgGMTV1 infection interferes with host RNA silencing. In addition, the relative proportions of the different sRNA lengths were altered in the S-AB and S-ABC libraries. The genome distribution patterns of the mapping of vsiRNA to DNA-A and DNA-B in the S-AB and S-ABC libraries were also different. These results suggest the influence of DNA-C on host RNA silencing. Transcripts targeted by vsiRNAs were enriched in pathways that included flavin adenine dinucleotide binding, protein folding, and filamentous growth.

6.
J Fungi (Basel) ; 8(11)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36354938

RESUMO

Fungal viruses are widespread in fungi infecting plants, insects and animals. High-throughput sequencing has rapidly led to the discovery of fungal viruses. However, the interactive exploration between fungi and viruses is relatively limited. RNA silencing is the fundamental antivirus pathway in fungi. Fusarium graminearum small RNA (sRNA) pattern was regulated by Fusarium graminearum hypovirus 1 (FgHV1) infection, indicating the activation of RNA silencing in virus defense. In this study, we focused on the function of an uncharacterized protein sized at 20 kD (p20) encoded by FgHV1. In the agro-infiltration assay, p20 was identified as a novel fungal RNA silencing suppressor. p20 can block systemic RNA silencing signals besides local RNA silencing suppression. We further elucidated the RNA silencing suppression mechanism of p20. The single-strand sRNA, instead of double-strand sRNA, can be incorporated by p20 in electrophoretic mobility shift assay. p20 binds sRNA originating from virus and non-virus sources in a non-sequence-specific manner. In addition, The F. graminearum 22 and 23-nt sRNA abundance and pathways related to RNA processing and redox regulation were regulated by p20. Our study revealed the first fungal virus-encoded RNA silencing suppressor with sRNA binding capability.

7.
Front Plant Sci ; 13: 937414, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35909738

RESUMO

The citrus orchards in southern China are widely threatened by low soil pH and Huanglongbing (HLB) prevalence. Notably, the lime application has been used to optimize soil pH, which is propitious to maintain root health and enhance HLB tolerance of citrus; however, little is known about the interactive effects of soil acidity on the soil properties and root-associated (rhizoplane and endosphere) microbial community of HLB-infected citrus orchard. In this study, the differences in microbial community structures and functions between the acidified and amended soils in the Gannan citrus orchard were investigated, which may represent the response of the host-associated microbiome in diseased roots and rhizoplane to dynamic soil acidity. Our findings demonstrated that the severity of soil acidification and aluminum toxicity was mitigated after soil improvement, accompanied by the increase in root activity and the decrease of HLB pathogen concentration in citrus roots. Additionally, the Illumina sequencing-based community analysis showed that the application of soil amendment enriched functional categories involved in host-microbe interactions and nitrogen and sulfur metabolisms in the HLB-infected citrus rhizoplane; and it also strongly altered root endophytic microbial community diversity and structure, which represented by the enrichment of beneficial microorganisms in diseased roots. These changes in rhizoplane-enriched functional properties and microbial composition may subsequently benefit the plant's health and tolerance to HLB disease. Overall, this study advances our understanding of the important role of root-associated microbiota changes and ecological factors, such as soil acidity, in delaying and alleviating HLB disease.

8.
Arch Virol ; 167(3): 969-972, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35112200

RESUMO

Nematodes are abundant, but little is known about their viruses. In this study, we report a novel partitivirus isolated from the entomopathogenic nematode species Steinernema ceratophorum, named "Steinernema ceratophorum partitivirus 1" (ScPV-1). The complete genome of ScPV-1 comprises two dsRNA segments, dsRNA1 (2352 bp) and dsRNA2 (2196 bp). Each dsRNA contains a single open reading frame (ORF), encoding a putative RNA-dependent RNA polymerase (RdRp) and a coat protein (CP), respectively. The sequences of the RdRp and CP showed the highest similarity (47% and 33% identity, respectively) to Plasmopara viticola associated partitivirus 7 (PvAP-7). A multiple sequence alignment and phylogenetic analysis of the RdRp of ScPV-1 and other selected viruses indicated that ScPV-1 is a new member of the genus Betapartitivirus in the family Partitiviridae.


Assuntos
Nematoides , Vírus de RNA , Animais , Genoma Viral , Nematoides/genética , Filogenia , Vírus de RNA/genética , RNA Viral/genética
9.
J Environ Manage ; 306: 114406, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35016142

RESUMO

Nitrogen pollutants such as ammonia and nitrates cause soil and groundwater contamination at municipal solid waste landfill (MSWL) sites due to leachate leakage. Here, the migration of nitrogen pollutants in the vadose zone of the red bed (VZRB) at a MSWL site was studied by static adsorption batch experiments and one-dimensional simulated migration experiments. The results indicated that the soil in the red bed did not adsorb nitrates. Chemical adsorption and monolayer adsorption of the soil played dominant roles during ammonia adsorption in the VZRB, which was best fitted by the pseudo-second-order kinetic equation ( [Formula: see text] = 0.99) and the Langmuir model. The ammonia adsorption capacity of the soil was the highest (Qm = 2.041 mg·g-1) at 318 K. It was due to the endothermic and non-spontaneous chemical adsorption of ammonia, whose enthalpy change (ΔH) reached 20.995 kJ·mol-1 and Gibbs free energy ranged from 8.469 to 8.706 kJ·mol-1. Chloride penetration tests indicated that the diffusion coefficient and migration speed reached 0.0515 cm2·h-1 and 0.0833 cm·h-1, respectively, in the clay layer under the MSWL sites. The average hysteresis diffusion coefficients of ammonia in the simulated soil columns leached by ammonium chloride solution (SSCAC) and by the leachate from MSWL (SSCL) were 1.129 and 1.400, respectively. After the leaching experiments, the clay pore structure was saturated, and the specific surface area decreased. The absorption peak intensities of clay functional groups, including carboxyl, alkyne, and hydroxyl groups, were reduced. The ammonia content in the soil of SSCAC decreased from the top (14.51 mg·kg-1) to the bottom (3.14 mg·kg-1) and in the SSCL from 24.96 mg·kg-1 to 5.05 mg·kg-1, respectively. Thus, the impermeable clay layer and VZRB helped in retardation of ammonia leakage from MSWL sites. This was due to the blockage of seepage, ammonia mechanical filtration, ammonia monolayer chemical adsorption, and the reaction between the functional groups and ammonia in the VZRB underneath the MSWL sites.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Nitrogênio , Resíduos Sólidos , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise
10.
Waste Manag ; 139: 330-340, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35007953

RESUMO

The environmental risk assessment and the factors influencing heavy metals (HM) in the soil at the municipal solid waste landfill sites (MSWLs) were studied by literature review, field survey, and statistical methods. The results indicated that the dominant HM contamination in the soil at the MSWLs was caused by chromium (Cr) with the Nemero index values (PI) from 22.7 to 44.3 and zinc (Zn) with the PI from 0.7 to 9.8. There were significant differences in the Cr, mercury (Hg), lead (Pb), Zn, and arsenic (As) concentrations between soil samples from sanitary and non-sanitary landfills (NSLs) where HM contamination (PI = 10.9) was more obvious. As (CRAAs = 2.35 × 10-4) and cadmium (Cd) (CRACd = 1.45 × 10-4) posed potential carcinogenic health effects. The soil Cd concentration had a significant negative correlation (r = -0.476**) with the landfill age. The soil As concentration had a significant positive correlation (r = 0.472**) with rainfall in NSLs. There were significant differences in the As (P = 0.042) and copper (Cu) (P = 0.042) concentrations between soil samples from the surrounding areas of MSWLs and the base where soil had higher HM concentrations. For the efficient prevention of HM ecological risk, a scientific site selection, undamaged coverage and anti-seepage systems, standardized management, and ongoing monitoring are required.


Assuntos
Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos
11.
Front Plant Sci ; 12: 656997, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33953735

RESUMO

Huanglongbing (HLB) is the most destructive citrus disease worldwide. This is associated with the phloem-limited bacterium Candidatus Liberibacter, and the typical symptom is leaf blotchy mottle. To better understand the biological processes involved in the establishment of HLB disease symptoms, the comparative proteomic analysis was performed to reveal the global protein accumulation profiles in leaf petiole, where there are massive HLB pathogens of Ca. L. asiaticus-infected Newhall sweet orange (Citrus sinensis) plants at the asymptomatic and symptomatic stages compared to their healthy counterpart. Photosynthesis, especially the pathway involved in the photosystem I and II light reactions, was shown to be suppressed throughout the whole Ca. L. asiaticus infection cycle. Also, starch biosynthesis was induced after the symptom-free prodromal period. Many defense-associated proteins were more extensively regulated in the petiole with the symptoms than the ones from healthy plants. The change of salicylic and jasmonic acid levels in different disease stages had a positive correlation with the abundance of phytohormone biosynthesis-related proteins. Moreover, the protein-protein interaction network analysis indicated that an F-type ATPase and an alpha-1,4 glucan phosphorylase were the core nodes in the interactions of differentially accumulated proteins. Our study indicated that the infected citrus plants probably activated the non-unified and lagging enhancement of defense responses against Ca. L. asiaticus at the expense of photosynthesis and contribute to find out the key Ca. L. asiaticus-responsive genes for tolerance and resistance breeding.

12.
Plant Dis ; 105(10): 3276-3278, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33970680

RESUMO

Xenorhabdus budapestensis strain C72 isolated from the entomopathogenic nematode of Steinernema bicornutum possesses an excellent biocontrol effect on southern corn leaf blight. However, its genomic information is lacking. Here, we report a high-quality complete and annotated genome sequence of X. budapestensis strain C72. Fifteen secondary metabolite biosynthetic gene clusters are identified in the genome, which are responsible for the production of a diverse group of antimicrobial compounds to help host plants against agricultural pathogenic diseases. This genome sequence could contribute to investigations of the molecular basis underlying the biocontrol activity of this Xenorhabdus strain.


Assuntos
Xenorhabdus , Agentes de Controle Biológico , China , Análise de Sequência de DNA , Xenorhabdus/genética
13.
Waste Manag ; 118: 445-451, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32971379

RESUMO

This study investigated the morphology and potentially toxic metal concentrations of paper waste-based biochar (PB) and kitchen waste-based biochar (KB) obtained at 500 and 700 °C. The morphology and potentially toxic metals (Cr, Mn, Cu, Cd, Pb, Zn, Ag, and Ba) concentrations in the biochars were determined by SEM and FT-IR analysis. The Cr, Mn, Cu, and Cd concentrations in PB were low, while the Ba content was relatively high at 0.1 mg∙kg-1. An increase in the terminal temperature led to an increase in the concentrations of Fe/Mn oxide-bound potentially toxic metals of PB, and a decrease in the concentrations of organic matter-bound potentially toxic metals. The Fe/Mn oxide-bound Cr, Mn, Cu, Pb, and Zn concentrations of KB decreased with an increase in the terminal temperature. Therefore, increasing the terminal temperature could reduce the bioavailability of potentially toxic metals in PB and KB. The environmental risk of the different biochars when used for soil remediation was assessed by the potential ecological risk index (RI), and a case study of a Tibetan soil was also conducted. The potentially toxic metal concentrations leached from both PB and KB were lower than the relevant standards. The findings showed that both PB and KB can be safely used for soil remediation.


Assuntos
Metais Pesados , Poluentes do Solo , Carvão Vegetal , Monitoramento Ambiental , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
14.
Arch Virol ; 165(12): 2979-2983, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32902666

RESUMO

To our knowledge, no mycoviruses have been reported in Fusarium cerealis. Here, we describe a novel double-stranded RNA (dsRNA) virus, Fusarium cerealis partitivirus 1 (FcPV1), isolated from F. cerealis strain HN30 from Henan Province, China. The FcPV1 genome consists of two dsRNA segments, 1732 bp (dsRNA1) and 1361 bp (dsRNA2) in length, each containing a single open reading frame potentially encoding a 61.0-kDa protein and a 42.0-kDa protein, respectively. dsRNA1 encodes a putative RNA-dependent RNA polymerase (RdRp), while the dsRNA2 product has no significant similarity to any other capsid proteins (CPs) in the GenBank databases other than limited similarity to hypothetical "capsid" proteins of a few partitiviruses. Sequence alignments and phylogenetic analysis showed that FcPV1 is related to members of the newly proposed genus "Zetapartitivirus" in the family Partitiviridae.


Assuntos
Micovírus/classificação , Fusarium/virologia , Genoma Viral , Filogenia , RNA de Cadeia Dupla/genética , Sequência de Aminoácidos , Proteínas do Capsídeo/genética , China , Micovírus/isolamento & purificação , Fases de Leitura Aberta , Doenças das Plantas/microbiologia , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , Alinhamento de Sequência
15.
Waste Manag ; 114: 115-123, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32659684

RESUMO

The biogas generation mechanism and its utilization potential in a novel spatiotemporally anaerobic/semi-aerobic bioreactor (STASAB) system with three activated bioreactors (C1, C2 and C3) was analyzed. Methane generation potential was obtained by measurements and estimation methods with similar values of 23.38 and 27.79 kg CH4/t waste, respectively. CH4 and CO2 production was quickly achieved in the STASAB, and the total amount of CH4 and CO2 was low due to the mixed leachate-recirculation operation process among bioreactors, which were at different stages of operation. The microbial communities in different bioreactors were diverse. The leachate-recirculation operation was a critical parameter to effectively enhance the microbial community structure in the STASAB, which can regulate CH4, CO2 and N2O production with global warming potential of 7.479 kg CO2e/(t·d). The STASAB had higher energy potential of 1.011 kWh/(t·d) compared with that of conventional landfills and sequentially anaerobic/semi-aerobic bioreactors. Moreover, direct electricity production in the STASAB is recommended for energy utilization with 38.38% GHG emission reduction, and with 131.43 million CNY (Chinese Yuan) benefit per year for national rural waste disposal via utilization of biogas from the STASAB for power generation. Hence, the STASAB shows a notable potential for treating domestic waste in rural areas.


Assuntos
Carbono , Eliminação de Resíduos , Anaerobiose , Reatores Biológicos , Metano , Instalações de Eliminação de Resíduos
16.
J Environ Manage ; 268: 110661, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32510430

RESUMO

Nitrogen contamination of groundwater has become a global issue and has aroused considerable concern among authorities. However, it is difficult to trace nitrogen sources in settings where a municipal solid waste (MSW) landfill site co-exists with intensive agriculture and other human activities. Therefore, a field investigation that combined a statistical analysis (factor analysis: FA) and hydrochemical analysis was designed and undertaken to identify nitrogen-pollutant sources in the shallow groundwater beneath an MSW landfill near to an agricultural area and human settlement. The results of the case study showed that nitrate was the specific pollutant produced by agricultural non-point-sources (Pbi = 15.5) and domestic pollution sources (Pbi = 41.0). The total phosphorus (Pbi = 37.2) and organic matter (Pbi = 16.6) were the specific pollutants released by the aquaculture and animal husbandry point-sources, and chloride (Pbi = 75.4) and organic matter (Pbi = 16.1) were the specific pollutants produced by the landfill. In the investigated area, the domestic pollution sources and agricultural non-point-sources were the most likely sources of nitrate contamination in the shallow aquifer. However, the landfill source and the aquaculture and animal husbandry point sources were the most likely sources of ammonium contamination. The combined method used in this study could successfully identify the nitrogen pollution sources in the shallow groundwater beneath an MSW landfill located in the vicinity of multiple pollutant sources. The method could be used to improve the control of nitrogen contamination and the management of groundwater quality.


Assuntos
Poluentes Ambientais , Água Subterrânea , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Humanos , Nitrogênio , Resíduos Sólidos , Instalações de Eliminação de Resíduos
17.
Int J Mol Sci ; 21(10)2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32443846

RESUMO

Huanglongbing (HLB) is a devastating citrus disease that has caused massive economic losses to the citrus industry worldwide. The disease is endemic in most citrus-producing areas of southern China, especially in the sweet orange orchards where soil acidification has intensified. In this work, we used lime as soil pH amendment to optimize soil pH and enhance the endurance capacity of citrus against Candidatus Liberibacter asiaticus (CLas). The results showed that regulation of soil acidity is effective to reduce the occurrence of new infections and mitigate disease severity in the presence of HLB disease. We also studied the associated molecular mechanism and found that acid soil improvement can (i) increase the root metabolic activity and up-regulate the expression of ion transporter-related genes in HLB-infected roots, (ii) alleviate the physiological disorders of sieve tube blockage of HLB-infected leaves, (iii) strengthen the citrus immune response by increasing the expression of genes involved in SAR and activating the salicylic acid signal pathway, (iv) up-regulate 55 proteins related to stress/defence response and secondary metabolism. This study contributes to a better understanding of the correlation between environment factors and HLB disease outbreaks and also suggests that acid soil improvement is of potential value for the management of HLB disease in southern China.


Assuntos
Citrus/imunologia , Produção Agrícola/métodos , Resistência à Doença , Genes de Plantas , Solo/química , Ácidos/análise , Citrus/genética , Citrus/microbiologia , Liberibacter/patogenicidade
18.
Sci Adv ; 6(14): eaay9634, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32284975

RESUMO

Here, we describe a tripartite circular single-stranded (ss) DNA mycovirus, named Fusarium graminearum gemytripvirus 1 (FgGMTV1). The genome of FgGMTV1 comprises three circular ssDNA segments (DNA-A, DNA-B, and DNA-C). Sequence alignments and phylogenetic analyses showed that FgGMTV1 is nested within the family Genomoviridae. We also constructed the first infectious DNA clones of a DNA mycovirus. Our results show that DNA-A and DNA-B are mutually interdependent for their replication and are associated with severely reduced colony growth and hypovirulence. DNA-C relies on DNA-A and DNA-B for replication and is necessary for the recovery of abnormal fungal phenotypes. DNA-C also enhances the accumulation of viral DNA in infected fungi and permits stable colonization and easy transmission via conidia. This is the first multipartite DNA virus isolated from a fungus. Our phylogenetic analyses also suggest that the multipartite genome of FgGMTV1 may have evolved from a monopartite genome of an ancient genomovirus.


Assuntos
DNA de Cadeia Simples , Micovírus/classificação , Micovírus/genética , Vírion , Clonagem Molecular , DNA Viral , Micovírus/isolamento & purificação , Genoma Viral , Filogenia , Doenças das Plantas/microbiologia , Sequenciamento Completo do Genoma
19.
Viruses ; 12(3)2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32213895

RESUMO

Fungal viruses (mycoviruses) have attracted more attention for their possible hypovirulence (attenuation of fungal virulence) trait, which may be developed as a biocontrol agent of plant pathogenic fungi. However, most discovered mycoviruses are asymptomatic in their hosts. In most cases, mycovirus hypovirulent factors have not been explored clearly. In this study, we characterized a ssRNA mycovirus in Fusarium graminearum strain HB56-9. The complete nucleotide genome was obtained by combining random sequencing and rapid amplification of cDNA ends (RACE). The full genome was 6621-nucleotides long, excluding the poly(A) tail. The mycovirus was quite interesting because it shared 95.91% nucleotide identities with previously reported Fusarium graminearum virus 1 strain DK21 (FgV1-DK21), while the colony morphology of their fungal hosts on PDA plates were very different. The novel virus was named Fusarium graminearum virus 1 Chinese isolate (FgV1-ch). Like FgV1-DK21, FgV1-ch also contains four putative open reading frames (ORFs), including one long and three short ORFs. A phylogenetic analysis indicated that FgV1-ch is clustered into a proposed family Fusariviridae. FgV1-ch, unlike FgV1-DK21, had mild or no effects on host mycelial growth, spore production and virulence. The nucleotide differences between FgV1-ch and FgV1-DK21 will help to elucidate the hypovirulence determinants during mycovirus-host interaction.


Assuntos
Micovírus/classificação , Micovírus/fisiologia , Fusarium/virologia , Sequência de Aminoácidos , Biologia Computacional , Interações Hospedeiro-Patógeno , Filogenia , Doenças das Plantas , Vírus de RNA/genética , RNA de Cadeia Dupla , Sequenciamento Completo do Genoma
20.
Pest Manag Sci ; 76(1): 236-243, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31149755

RESUMO

BACKGROUND: Sitobion avenae, a dominant aphid in wheat that causes huge annual losses in agriculture, is mainly controlled using chemical pesticides. In this study, we investigated a protein elicitor, PeaT, for its induction of the defense response in wheat against Sitobion avenae. RESULTS: Intrinsic rates of increase in second and third generations of S. avenae decreased in the PeaT1 (second generation 0.31 ± 0.01, third generation 0.28 ± 0.01) treatment compared with controls (second generation 0.28 ± 0.01, third generation 0.26 ± 0.01). S. avenae preferred to colonize control rather than PeaT1-treated wheat seedlings in a host selection test. PeaT1-treated wheat leaves possessed more trichomes and wax that formed a disadvantageous surface environment for S. avenae. Both salicylic acid (SA) and jasmonic acid (JA) accumulated significantly in PeaT1-treated wheat seedlings. CONCLUSION: These results showed that PeaT1 modified physical surface structures in wheat to reduce reproduction and deter colonization by S. avenae. SA and JA were involved in the induced physical defense process. This study provided evidence for use of PeaT1 as a 'vaccine' to protect wheat from Sitobion avenae. © 2019 Society of Chemical Industry.


Assuntos
Afídeos , Animais , Comportamento Alimentar , Folhas de Planta , Ácido Salicílico , Triticum
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...