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1.
Arch Virol ; 165(3): 789-791, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32002667

RESUMO

A novel virus of the genus Narnavirus, designated "Saccharomyces narnavirus I329" (ScNV-I329), was discovered in Saccharomyces cerevisiae strain I-329, which is used for industrial production of sherry-like wines. The genome of ScNV-I329 is 2509 nt in length with short terminal inverted repeats and a single open reading frame capable of encoding an RNA-dependent RNA polymerase most closely related to that of Saccharomyces 20S RNA narnavirus. This is the third known member of the genus Narnavirus from yeasts.


Assuntos
Micovírus/isolamento & purificação , Micovírus/fisiologia , Saccharomyces cerevisiae/virologia , Micovírus/genética , Filogenia , Saccharomyces cerevisiae/classificação
2.
Arch Virol ; 165(3): 785-788, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31980938

RESUMO

In this study, the complete genomic sequence of a novel botoulivirus (Sclerotinia minor botoulivirus 1, SmBV1) from the phytopathogenic fungus Sclerotinia minor strain LC45 was determined. The genome of SmBV1 is 2,882 nucleotides in length and contains a single large open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis showed that SmBV1 clustered with the botoulivirus clade within the family Botourmiaviridae. This is the first report of a botoulivirus in S. minor.


Assuntos
Ascomicetos/virologia , Micovírus/isolamento & purificação , Micovírus/fisiologia , Sequência de Aminoácidos , Micovírus/genética , Filogenia , Proteínas Virais/genética , Proteínas Virais/metabolismo
3.
Arch Virol ; 164(12): 3141-3144, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31598844

RESUMO

In this study, we report a novel double-stranded RNA (dsRNA) virus, Beauveria bassiana partitivirus 3 (BbPV-3), derived from the entomogenous fungus Beauveria bassiana isolate RCEF5853 from China. The genome of BbPV-3, whose sequence was determined by metagenomic sequencing, RT-PCR, and RACE cloning, comprises two dsRNA genome segments that are 1,856 and 1,719 bp long. The first segment contains a single ORF (ORF-1) encoding a 584-amino-acid-long protein (66.05 kDa) with a conserved RNA-dependent RNA polymerase (RdRp) motif. The second segment also has a single ORF (ORF-2) encoding a 500-amino-acid-long coat protein (CP) (55.9 kDa). The CP and RdRp sequences showed highest identity of 43.4% and 60.2%, respectively, to those of Colletotrichum eremochloae partitivirus 1. Phylogenetic analysis of the RdRp domain of the polyprotein revealed that BbPV-3 grouped together with the members of the genus Epsilonpartitivirus. Hence, we proposed that Beauveria bassiana partitivirus 3 is a novel member of the proposed genus Epsilonpartitivirus.


Assuntos
Beauveria/virologia , Micovírus/isolamento & purificação , Genoma Viral , Vírus de RNA/isolamento & purificação , Sequência de Bases , China , Micovírus/classificação , Micovírus/genética , Filogenia , RNA Replicase/genética , Vírus de RNA/classificação , Vírus de RNA/genética , RNA Viral/genética , Proteínas Virais/genética , Sequenciamento Completo do Genoma
4.
Virol J ; 16(1): 113, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511029

RESUMO

BACKGROUND: Trichoderma spp. are used extensively in agriculture as biological control agents to prevent soil-borne plant diseases. In recent years, mycoviruses from fungi have attracted increasing attention due to their effects on their hosts, but Trichoderma mycoviruses have not been the subject of extensive study. We sought to discover novel mycoviruses from Trichoderma spp. and to determine the effects of the biocontrol function of Trichoderma spp. METHODS: Mycoviruses were screened by dsRNA extraction and metagenomic analysis. RT-PCR, 5' RACE, and 3' RACE were used to obtain the genome sequence. MEGA software was used to classify the new mycovirus. The effects of the identified mycovirus on the biological properties of the host strain 525 were evaluated using cucumber plants and Fusarium oxysporum f. sp. cucumerinum. RESULTS: A novel mycovirus, Trichoderma harzianum mycovirus 1 (ThMV1) (accession number MH155602), was discovered in Trichoderma harzianum strain 525, a soil-borne fungus collected from Inner Mongolia, China. The mycovirus exhibited a double-stranded RNA (dsRNA) genome with a complete genome sequence of 3160 base pairs and two open reading frames (ORFs) on the negative strand. Phylogenetic analysis indicated that it belongs to an unclassified family of dsRNA mycoviruses. The removal of ThMV1 from the host 525 strain reduced host biomass production and improved the biocontrol capability of the host for Fusarium oxysporum f. sp. cucumerinum. At same time, the presence of ThMV1 improved the growth of cucumber. CONCLUSION: ThMV1 is a new unclassified mycovirus found in T. harzianum. It not only affects the phenotype of the host strain but also reduces its biocontrol function, which sheds light on the interaction between the mycovirus and Trichoderma spp.


Assuntos
Micovírus/genética , Micovírus/isolamento & purificação , Vírus de RNA/isolamento & purificação , RNA de Cadeia Dupla , Trichoderma/virologia , Agentes de Controle Biológico , Metagenômica , Fases de Leitura Aberta , RNA Viral/genética , Sequenciamento Completo do Genoma
5.
Arch Virol ; 164(11): 2859-2863, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31385115

RESUMO

In this study, we report the molecular characterization of a novel mycovirus in a phytopathogenic fungus of the species Colletotrichum gloeosporioides, which we named "Colletotrichum gloeosporioides RNA virus 1" (CgRV1). The virus has a dsRNA genome of 2,975 bp and possesses two non-overlapping open reading frames (ORFs 1 and 2). The smaller ORF1 encodes a protein of unknown function, and the larger ORF2 encodes the RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis based on the RdRp sequence showed that CgRV1 clustered with and is closely related to unclassified mycoviruses that are distinct from members of the family Partitiviridae.


Assuntos
Colletotrichum/virologia , Micovírus/genética , Genoma Viral/genética , Vírus não Classificados/genética , Sequência de Aminoácidos , Micovírus/isolamento & purificação , Fases de Leitura Aberta/genética , Doenças das Plantas/microbiologia , RNA Viral/genética , Vírus não Classificados/isolamento & purificação
6.
Arch Virol ; 164(10): 2631-2635, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31367950

RESUMO

In this study, a novel mycovirus designed Colletotrichum gloeosporioides ourmia-like virus 1 (CgOLV1) was isolated from a filamentous phytopathogenic fungus, Colletotrichum gloeosporioides. The virus has a genome of 2,516 nucleotides and contains a large open reading frame (ORF) encoding an RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis indicated that CgOLV1 is located in the ourmia-like mycovirus clade, whose members are related to plant ourmiaviruses. To the best of our knowledge, this is the first report of an ourmia-like mycovirus in C. gloeosporioides.


Assuntos
Colletotrichum/virologia , Micovírus/classificação , Micovírus/isolamento & purificação , Filogenia , Micovírus/genética , Genoma Viral , Fases de Leitura Aberta , Doenças das Plantas/microbiologia , RNA Replicase/genética , Análise de Sequência de DNA
7.
Arch Virol ; 164(11): 2853-2857, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377887

RESUMO

A double-stranded RNA (dsRNA) segment was extracted from the ectomycorrhizal fungus Geopora sumneriana (Cooke) M. Torre, and its full-length cDNA sequence, comprising 3146 nucleotides, was determined. Sequence analysis revealed the presence of a large open reading frame (ORF) on the positive strand of this dsRNA segment when the mold mitochondrial genetic code was applied. The ORF encodes a putative RNA-dependent RNA polymerase (RdRp), which shares the highest degree of similarity with Tuber excavatum mitovirus, with 37.52% identity. This dsRNA segment represents the genome replication intermediate of a novel mitovirus that was tentatively designated as "Geopora sumneriana mitovirus 1" (GsMV1). Phylogenetic analysis further suggested that GsMV1 is a member of the family Narnaviridae. This is the first study reporting on a mitovirus genome sequence in the ectomycorrhizal fungus G. sumneriana.


Assuntos
Colletotrichum/virologia , Micovírus/classificação , Micovírus/genética , Genoma Viral/genética , Sequência de Aminoácidos , Sequência de Bases , Micovírus/isolamento & purificação , Fases de Leitura Aberta/genética , RNA Replicase/genética , RNA Viral/genética , Análise de Sequência de RNA , Sequenciamento Completo do Genoma
8.
Arch Virol ; 164(10): 2545-2549, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31317260

RESUMO

A novel bisegmented double-stranded RNA virus was identified in the mycoparasitic and opportunistic fungus Hypomyces chrysospermus. The RNA1 genome segment comprises 1866 bp and encodes an RNA-dependent RNA polymerase (RdRp). The RNA2 segment comprises 1822 bp and encodes a capsid protein. Phylogenetic analysis of the RdRp protein indicated that this virus is a new member of genus Alphapartitivirus in the family Partitiviridae. We have designated this mycovirus as "Hypomyces chrysospermus partitivirus 1" (HcPV1). HcPV1 is highly transmissible with aleurioconidia and is present in large amounts within growing mycelium in comparison to the GAPDH reference gene.


Assuntos
Micovírus/classificação , Micovírus/isolamento & purificação , Hypocreales/virologia , Filogenia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , Proteínas do Capsídeo/genética , Micovírus/genética , Genoma Viral , RNA Replicase/genética , Vírus de RNA/genética , Análise de Sequência de DNA
9.
Virology ; 533: 125-136, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31153047

RESUMO

There is still limited information on the diversity of (-)ssRNA viruses that infect fungi. Here, we have discovered two novel (-)ssRNA mycoviruses in the shiitake mushroom (Lentinula edodes). The first virus has a monopartite RNA genome and relates to that of mymonaviruses (Mononegavirales), especially to Hubei rhabdo-like virus 4 from arthropods and thus designated as Lentinula edodes negative-strand RNA virus 1. The second virus has a putative bipartite RNA genome and is related to the recently discovered bipartite or tripartite phenui-like viruses (Bunyavirales) associated with plants and ticks, and designated as Lentinula edodes negative-strand RNA virus 2 (LeNSRV2). LeNSRV2 is likely the first segmented (-)ssRNA virus known to infect fungi. Its smaller RNA segment encodes a putative nucleocapsid and a plant MP-like protein using a potential ambisense coding strategy. These findings enhance our understanding of the diversity, evolution and spread of (-)ssRNA viruses in fungi.


Assuntos
Micovírus/isolamento & purificação , Vírus de RNA/isolamento & purificação , Cogumelos Shiitake/virologia , Sequência de Bases , Micovírus/genética , Filogenia , Vírus de RNA/classificação , Vírus de RNA/genética , RNA Viral/genética
10.
Arch Virol ; 164(9): 2411-2416, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31254049

RESUMO

Macrophomina phaseolina is a pathogenic fungus of the family Botryosphaeriaceae that causes stem rot or leaf blight in many economically important plants. Mycoviruses exist widely in fungi, but there are only a limited number of reports on mycovirus infection in M. phaseolina. A novel dsRNA virus, tentatively named "Macrophomina phaseolina fusagravirus 1" (MpFV1), was isolated from strain 2012-19 of M. phaseolina, and its molecular features were examined. The full-length cDNA of MpFV1 comprises 9,289 nucleotides with a predicted GC content of 48.1% and two discontinuous open reading frames (ORF 1 and 2). A-1 frameshift region with two typical factors, including a shifty heptamer (GGAAAAC) and an H-type pseudoknot, was predicted in the junction region of ORF1 and ORF2. The protein encoded by ORF1 shows significant similarity to a hypothetical protein, whereas ORF2 encodes an RNA-dependent RNA polymerase (RdRp) via a ribosomal frameshifting mechanism. Homology searches and phylogenetic analysis based on the RdRp sequence suggested that MpFV1 is a new member of the proposed family "Fusagraviridae".


Assuntos
Ascomicetos/virologia , Micovírus/isolamento & purificação , Vírus de RNA/isolamento & purificação , Mudança da Fase de Leitura do Gene Ribossômico , Micovírus/classificação , Micovírus/genética , Fases de Leitura Aberta , Filogenia , RNA Replicase/genética , Vírus de RNA/classificação , Vírus de RNA/genética , Proteínas Virais/genética
11.
Virology ; 534: 25-35, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31170545

RESUMO

Three ourmia-like viruses, designated Pyricularia oryzae ourmia-like virus (PoOLV) 1 to 3, were identified in a wheat-infecting isolate of P. oryzae. The sizes of the full-length PoOLV1-3 genomes were determined to be 2,528, 1,671, and 2,557 nt. Interestingly, we also found two abundant single-stranded RNAs sharing their 5' terminal 25 and 255 nt with PoOLV1 RNA and PoOLV3 RNA, respectively. The PoOLV1- and PoOLV3-associated RNAs (ARNA1 and ARNA3) were 639 and 514 nt in length, and possessed one and two small ORFs, respectively. In the field isolates of P. oryzae, PoOLVs and ARNAs were detectable at varying levels, and the levels of PoOLV1 and ARNA1 as well as those of PoOLV3 and ARNA3, were tightly correlated. In addition, gene silencing of PoOLV1 and PoOLV3 resulted in a reduction of ARNA1 and ARNA3, respectively. There results indicated that replication of ARNA1 and ARNA3 was associated with PoOLV1 and PoOLV3, respectively.


Assuntos
Ascomicetos/virologia , Micovírus/isolamento & purificação , Doenças das Plantas/microbiologia , RNA Viral/metabolismo , Micovírus/classificação , Micovírus/genética , Genoma Viral , Fases de Leitura Aberta , Filogenia , RNA Viral/genética , Triticum/microbiologia , Proteínas Virais/genética , Proteínas Virais/metabolismo
12.
Viruses ; 11(3)2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30841545

RESUMO

Here, the molecular characterization of a novel mycovirus that was isolated from a phytopathogenic fungus Magnaporthe oryzae and designed as Magnaporthe oryzae ourmia-like virus 4 (MOLV4) is reported. MOLV4 has a genome that is 2497 bp long and possesses a single open reading frame (ORF), which encodes the product RNA-dependent RNA polymerase (RdRp). Sequence similarities were found between the MOLV4 encoded RdRp and the counterparts of a few previously reported ourmia-like mycoviruses. Virus-curing and biological comparison indicate that the virus has no or mild effects on the morphology and mycelium growth rate of the host fungus. Phylogenetic analysis using the RdRp aa sequences was performed. The results show that MOLV4 is clustered with the ourmia-like mycoviruses, forming a clade closely related to ourmiaviruses but distinct from narnaviruses. In addition, database searches revealed that several MOLV4-related sequences are present in the transcriptome shotgun assembly (TSA) library, expressed sequence tag database (ESTdb), whole-genome shotgun (WGS) library, and genomic survey sequences (GSS) libraries of a few other species of eukaryote organisms. Our results show that MOLV4, together with other similar ourmia-like mycoviruses, might represent a virus clade that links the plant ourmiaviruses and fungal narnaviruses and has a wide range of hosts.


Assuntos
Micovírus/genética , Genoma Viral , Magnaporthe/virologia , Doenças das Plantas/microbiologia , Análise por Conglomerados , Biologia Computacional , Micovírus/isolamento & purificação , Fases de Leitura Aberta , Oryza/microbiologia , Filogenia , Vírus de RNA/genética , Vírus de RNA/isolamento & purificação , RNA Viral/genética , Análise de Sequência de DNA , Proteínas Virais/genética
13.
Arch Virol ; 164(5): 1479-1483, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30848387

RESUMO

Eight different double-stranded RNA (dsRNA) molecules were found in the wild-type fungal strain Botrytis cinerea CCg427. The electrophoretic profile displayed molecules with approximate sizes of 1, 1.3, 1.6, 1.8, 3.3, 4.1, 6.5, and 12 kbp. Sequences analysis of the molecules in the 6.5-kbp band revealed the presence of two different dsRNA molecules (dsRNA-1 and dsRNA-2) of 6192 and 5567 bp. Each molecule contained a unique ORF (5487 and 4836 nucleotides in dsRNA-1 and dsRNA-2, respectively). The ORF of dsRNA-1 encodes a 205-kDa polypeptide that shares 58% amino acid sequence identity with the RNA-dependent RNA polymerase (RdRp) encoded by dsRNA-1 of Alternaria sp. SCFS-3 botybirnavirus (ABRV1), whereas the ORF of dsRNA-2 encodes a 180-kDa polypeptide that shares 52% amino acid sequence identity with an unclassified protein encoded by dsRNA-2 of ABRV1. Genome organization and phylogenetic analysis based on the amino acid sequences of RdRps in members of different dsRNA virus families showed that the dsRNAs in the 6.5-kbp band correspond to the genome of a new botybirnavirus that we have named "Botrytis cinerea botybirnavirus 1".


Assuntos
Botrytis/virologia , Micovírus/genética , Genoma Viral/genética , Vírus de RNA/genética , RNA Viral/genética , Sequência de Aminoácidos , Micovírus/classificação , Micovírus/isolamento & purificação , Filogenia , RNA Replicase/genética , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , Proteínas Virais/genética
14.
Arch Virol ; 164(4): 1213-1216, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30746561

RESUMO

A new mycovirus was identified in Trichoderma harzianum strain 137 isolated in Xinjiang province, China. The whole genome sequence of the mycovirus was determined by metagenomic sequencing, RT-PCR, and RACE cloning. The mycovirus contained two genomic segments. The first segment was 2088 bp long and contained a single ORF (ORF1) encoding the RNA-dependent RNA polymerase (RdRP) (72.26 kDa). The second segment was 1634 bp long and also contained a single ORF (ORF2) encoding a hypothetical protein of 37.472 kDa. We named this novel mycovirus "Trichoderma harzianum bipartite mycovirus 1" (ThBMV1). Phylogenetic analysis showed that ThBMV1 clusters with other unclassified dsRNA mycoviruses.


Assuntos
Micovírus/isolamento & purificação , Genoma Viral , Trichoderma/virologia , Sequência de Bases , China , Micovírus/classificação , Micovírus/genética , Dados de Sequência Molecular , Filogenia , Proteínas Virais/genética , Sequenciamento Completo do Genoma
15.
Arch Virol ; 164(4): 1225-1228, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30805729

RESUMO

A new double-stranded RNA (dsRNA) virus named Alternaria alternata botybirnavirus 1 (AaBRV1) was isolated from Alternaria alternata strain SD-BZF-19, a phytopathogenic fungus infecting watermelon in China. The genome of AaBRV1 consists of two dsRNA segments (dsRNAs 1 and 2), 6,130 and 5,862 bp in size, respectively. The sequence contains two putative open reading frames (ORFs) which encode two polyproteins of 1,874 and 1,784 amino acids, respectively. Nucleotide sequence comparisons revealed that the two ORFs of AaBRV1 have the highest similarity 60.3% and 56.7%, respectively, with dsRNAs 1 and 2 of Botrytis porri RNA virus 1 (BpRV1). The two polyproteins encoded by dsRNA1 and dsRNA2 shared the highest amino acid identities with the cap-pol fusion protein (60.2%) and hypothetical protein (53.7%) of BpRV1, respectively. AaBRV1 is composed of isometric particles, approximately 35 nm in diameter. Phylogenetic analysis of the RNA dependent RNA polymerase (RdRp) domain of the polyprotein revealed that AaBRV1 clusters together with members of the genus Botybirnavirus. These findings support the discovery of a new botybirnavirus in A. alternata.


Assuntos
Alternaria/virologia , Micovírus/genética , Micovírus/isolamento & purificação , Genoma Viral , Vírus de RNA/genética , Vírus de RNA/isolamento & purificação , Sequência de Bases , China , Micovírus/classificação , Fases de Leitura Aberta , Filogenia , Vírus de RNA/classificação , Sequenciamento Completo do Genoma
16.
Arch Virol ; 164(3): 923-925, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30671654

RESUMO

A novel double-stranded RNA (dsRNA) mycovirus, named "Fusarium incarnatum alternavirus 1" (FiAV1), was found in Fusarium incarnatum strain LY003-07, the causal agent of peony root rot. The complete genome of FiAV1 is composed of three dsRNA segments, dsRNA1 (3548 nt), dsRNA2 (2514 nt), and dsRNA3 (2498 nt), with one open reading frame on each of their positive-sense strands. As found in other viruses of the proposed family Alternaviridae, the positive-sense strand of each genomic dsRNA of FiAV1 has a poly(A) tail and the 5'-terminal nonamer sequence 5'-GGCTGTGTG-3'. Based on a multiple sequence alignment and phylogenetic analysis based on the RdRps amino acid sequence, FiAV1 is suggested to be a new strain of a potential new species, for which the name "Fusarium alternavirus 1" is proposed, that includes Fusarium poae alternavirus 1 (FpAV1) and Fusarium graminearum alternavirus 1 (FgAV1/AH11) of the proposed family "Alternaviridae". This is the first report of a mycovirus of the proposed family "Alternaviridae" that infects F. incarnatum.


Assuntos
Micovírus/isolamento & purificação , Fusarium/virologia , Genoma Viral , Doenças das Plantas/microbiologia , Vírus de RNA/isolamento & purificação , Sequência de Bases , Micovírus/classificação , Micovírus/genética , Fusarium/fisiologia , Dados de Sequência Molecular , Fases de Leitura Aberta , Paeonia/microbiologia , Filogenia , Vírus de RNA/classificação , Vírus de RNA/genética , Sequenciamento Completo do Genoma
17.
Virus Res ; 263: 119-128, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30639468

RESUMO

Mycoviruses ubiquitously infect a wide range of fungal hosts in the world. The current study reports a novel double stranded RNA (dsRNA) virus, termed Alternaria alternata botybirnavirus 1 (AaBbV1), infecting a Pakistani strain, 4a, of a phytopathogenic ascomycetous fungus Alternaria alternata. A combined approach of next generation and conventional terminal end sequencing of the viral genome revealed that the virus is a distinct member of the genus Botybirnavirus. This virus comprised of two segments (dsRNA1 and dsRNA2) of sizes 6127 bp and 5860 bp respectively. The dsRNA1-encoded protein carrying the RNA-dependent RNA polymerase domain showed 61% identity to the counterpart of Botrytis porri botybirnavirus 1 and lower levels of amino acid similarity with those of other putative botybirnaviruses and the fungal dsRNA viruses such as members of the families Totiviridae, Chrysoviridae and Megabirnaviridae. The dsRNA2-encoded protein showed resemblance with corresponding proteins of botybirnaviruses. Electron microscopy showed AaBbV1 to form spherical particles of 40 nm in diameter. Biochemical analyses showed that two structural proteins encoded by dsRNA1 and dsRNA2 underwent processing to some extent during particle purification, resulting in the appearance of multiple smaller products. Phylogenetic analyses of structural proteins suggested that their coding region might have been duplicated once and maintained without recombination. Protoplast fusion technique allowed for the introduction of AaBbV1 into a virus free Japanese strain of A. alternata and demonstrated its symptomless infection by the virus. Interesting similarities and dissimilarities between AaBbV1 and other previously reported botybirnaviruses are also discussed.


Assuntos
Alternaria/virologia , Micovírus/classificação , Micovírus/isolamento & purificação , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , Análise por Conglomerados , Micovírus/genética , Micovírus/ultraestrutura , Genoma Viral , Microscopia Eletrônica , Paquistão , Filogenia , Processamento de Proteína Pós-Traducional , RNA Replicase/genética , Vírus de RNA/genética , Vírus de RNA/ultraestrutura , RNA de Cadeia Dupla/genética , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência , Proteínas Estruturais Virais/metabolismo , Vírion/ultraestrutura
18.
Arch Virol ; 164(3): 913-916, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30656466

RESUMO

Mycovirus infection is a universal phenomenon in the major fungus groups. So far, however, mycoviruses have not been described in the phytopathogenic fungus Leptosphaeria biglobosa, the causal agent of phoma stem canker (blackleg). Here, we report the complete genome sequence of a novel mitovirus, Leptosphaeria biglobosa mitovirus 1 (LbMV1), isolated from the strain H3-38 of L. biglobosa. The LbMV1 genome comprises 2568 nucleotides with a low G+C content of 30%. Using the mitochondrial genetic code, the genome of LbMV1 was found to contain a single large open reading frame that encodes a predicted protein of 756 amino acids. Multiple alignment of the predicted protein sequence showed the highest similarity (51% identity) to the putative RNA-dependent RNA polymerase of Ophiostoma mitovirus 4. In addition, phylogenetic analysis grouped LbMV1 within the genus Mitovirus of the family Narnaviridae. Our results suggest that the double-stranded RNA found in strain H3-38 is the replicating genome of the mitovirus LbMV1, its deletion represents the first evidence of a mycovirus infecting L. biglobosa.


Assuntos
Ascomicetos/virologia , Micovírus/isolamento & purificação , Doenças das Plantas/microbiologia , Vírus de RNA/isolamento & purificação , Ascomicetos/fisiologia , Micovírus/classificação , Micovírus/genética , Genoma Viral , Fases de Leitura Aberta , Filogenia , Vírus de RNA/classificação , Vírus de RNA/genética , RNA de Cadeia Dupla/genética
19.
Viruses ; 11(1)2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30609795

RESUMO

A pink isolate (QT5-19) of Botrytis cinerea was compared with three gray isolates of B. cinerea for growth and morphogenesis on potato dextrose agar (PDA), and for pathogenicity on tobacco. A double-stranded (ds) RNA mycovirus infecting QT5-19 was identified based on its genome feature and morphology of the virus particles. The results showed that QT5-19 grew rapidly and established flourishing colonies as the gray isolates did. However, it is different from the gray isolates, as it failed to produce conidia and sclerotia asthe gray isolates did. QT5-19 hardly infected tobacco, whereas the gray isolates aggressively infected tobacco. Two dsRNAs were detected in QT5-19, dsRNA 1 and dsRNA 2, were deduced to encode two polypepetides with homology to viral RNA-dependent RNA polymerase (RdRp) and coat protein (CP), respectively. Phylogenetic analysis of the amino acid sequences of RdRp and CP indicated that the two dsRNAs represent the genome of a novel partitivirus in the genus Alphapartitivirus, designated here as Botrytis cinerea partitivirus 2 (BcPV2). BcPV2 in QT5-19 was successfully transmitted to the three gray isolates through hyphal contact. The resulting BcPV2-infected derivatives showed rapid growth on PDA with defects in conidiogenesis and sclerogenesis, and hypovirulence on tobacco. This study suggests that BcPV2 is closely associated with hypovirulence of B. cinerea.


Assuntos
Botrytis/virologia , Micovírus/classificação , Genoma Viral , Botrytis/crescimento & desenvolvimento , Proteínas do Capsídeo/genética , Micovírus/isolamento & purificação , Filogenia , Pigmentação , Doenças das Plantas/microbiologia , RNA Replicase/genética , RNA de Cadeia Dupla , RNA Viral , Análise de Sequência de DNA , Esporos Fúngicos/crescimento & desenvolvimento , Tabaco/microbiologia
20.
Arch Virol ; 164(3): 897-901, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30600350

RESUMO

The complete genome of a novel mycovirus, Puccinia striiformis mitovirus 1 (PsMV1), derived from the wheat stripe rust fungus Puccinia striiformis strain SCSN-10, was sequenced and analyzed. The full-length cDNA sequence is 2496 bp in length with a predicted AU content of 57.65% in the genomic RNA. Sequence analysis indicated that a single large open reading frame (ORF) is present on the positive strand when the fungal mitochondrial genetic code is used. The single ORF encodes a putative RNA-dependent RNA polymerase of 743 amino acids with a molecular mass of 84.9 kDa that shares the closest similarity with the corresponding proteins of Cronartium ribicola mitovirus 5 and Helicobasidium mompa mitovirus 1-18 (34% and 35% aa sequence identity, respectively). Phylogenetic analysis further indicated that PsMV1 is a new member of the genus Mitovirus within the family Narnaviridae. This is the first report of the full-length nucleotide sequence of a novel mitovirus, PsMV1, from the causal agent of wheat stripe rust.


Assuntos
Basidiomycota/virologia , Micovírus/genética , Genoma Viral , Doenças das Plantas/microbiologia , Vírus de RNA/genética , Triticum/microbiologia , Sequência de Bases , Basidiomycota/fisiologia , Micovírus/classificação , Micovírus/isolamento & purificação , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação
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