scholarly journals Identification and characterization of two novel genomic RNA segments of fig mosaic virus, RNA5 and RNA6

2012 ◽  
Vol 93 (7) ◽  
pp. 1612-1619 ◽  
Author(s):  
Kazuya Ishikawa ◽  
Kensaku Maejima ◽  
Ken Komatsu ◽  
Yugo Kitazawa ◽  
Masayoshi Hashimoto ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Rna Virus ◽  
Mosaic Disease ◽  
The Novel ◽  
Genomic Rna ◽  
Evolutionary Patterns ◽  
Rna Molecules ◽  
Fig Mosaic Virus ◽  
Identification And Characterization

Fig mosaic virus (FMV), a negative-strand RNA virus, is recognized as a causal agent of fig mosaic disease. We performed RT-PCR for 14 FMV isolates collected from symptomatic fig plants in Japan and Serbia using primers corresponding to the conserved 13 nt stretches found at the termini of FMV genomic segments. The resulting simultaneous amplification of all FMV genomic segments yielded four previously identified segments of FMV and two novel segments. These novel FMV genomic RNA segments were found in each of the 14 FMV isolates analysed. In Northern blot studies, both the sense and antisense strands of these novel RNA molecules accumulated in FMV-infected fig leaves but not in uninfected fig leaves, confirming that they replicate as FMV genomic segments. Sequence analysis showed that the novel RNA segments are similar, in their structural organization and molecular evolutionary patterns, to those of known FMV genomic RNA segments. Our findings thus indicate that these newly discovered RNA segments are previously unidentified FMV genomic segments, which we have designated RNA5 and RNA6.

scholarly journals Genetic Variation and Possible Mechanisms Driving the Evolution of Worldwide Fig mosaic virus Isolates

2014 ◽  
Vol 104 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Jeewan Jyot Walia ◽  
Anouk Willemsen ◽  
Eminur Elci ◽  
Kadriye Caglayan ◽  
Bryce W. Falk ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Mosaic Virus ◽  
Rna Virus ◽  
Plant Viruses ◽  
Long Distance ◽  
Evolutionary Mechanisms ◽  
Plant Materials ◽  
Genomic Rnas ◽  
Fig Trees ◽  
Fig Mosaic Virus

Fig mosaic virus (FMV) is a multipartite negative-sense RNA virus infecting fig trees worldwide. FMV is transmitted by vegetative propagation and grafting of plant materials, and by the eriophyid mite Aceria ficus. In this work, the genetic variation and evolutionary mechanisms shaping FMV populations were characterized. Nucleotide sequences from four genomic regions (each within the genomic RNAs 1, 2, 3, and 4) from FMV isolates from different countries were determined and analyzed. FMV genetic variation was low, as is seen for many other plant viruses. Phylogenetic analysis showed some geographically distant FMV isolates which clustered together, suggesting long-distance migration. The extent of migration was limited, although varied, between countries, such that FMV populations of different countries were genetically differentiated. Analysis using several recombination algorithms suggests that genomes of some FMV isolates originated by reassortment of genomic RNAs from different genetically similar isolates. Comparison between nonsynonymous and synonymous substitutions showed selection acting on some amino acids; however, most evolved neutrally. This and neutrality tests together with the limited gene flow suggest that genetic drift plays an important role in shaping FMV populations.

scholarly journals Isolation and Characterization of a Novel Single-Stranded RNA Virus Infecting the Bloom-Forming Diatom Rhizosolenia setigera

2004 ◽  
Vol 70 (2) ◽  
pp. 704-711 ◽  
Author(s):  
Keizo Nagasaki ◽  
Yuji Tomaru ◽  
Noriaki Katanozaka ◽  
Yoko Shirai ◽  
Kensho Nishida ◽  
...  
Keyword(s):  
Host Specificity ◽  
Rna Virus ◽  
Biological Properties ◽  
Rna Molecules ◽  
Isolation And Characterization ◽  
Ssrna Virus ◽  
Ecological Relationship ◽  
Rhizosolenia Setigera ◽  
Species Specific

ABSTRACT A novel single-stranded RNA (ssRNA) virus specifically infecting the bloom-forming diatom Rhizosolenia setigera (R. setigera RNA virus [RsRNAV]) was isolated from Ariake Sea, Japan. Viral replication occurred within the cytoplasm, and the virus particle was icosahedral, lacked a tail, and was 32 nm in diameter on average. The major nucleic acid extracted from the RsRNAV particles was an ssRNA molecule 11.2 kb in length, although smaller RNA molecules (0.6, 1.2, and 1.5 kb) were occasionally observed. The major structural proteins of RsRNAV were 41.5, 41.0, and 29.5 kDa. Inter- and intraspecies host specificity tests revealed that RsRNAV is not only species specific but also strain specific and that its intraspecies host specificity is diverse among virus clones. The latent period of RsRNAV was 2 days, and the burst sizes were 3,100 and 1,010 viruses per host cell when viruses were inoculated into the host culture at the exponential and stationary growth phases, respectively, at 15°C under a 12-h-12-h light-dark cycle of ca. 110 μmol of photons m−2 s−1 with cool white fluorescent illumination. To our knowledge, this is the first report describing the biological properties of a virus infecting a diatom. Further studies on RsRNAV will be helpful in understanding the ecological relationship between diatoms and viruses in nature.

scholarly journals Identification and characterization of novel porcine astroviruses (PAstVs) with high prevalence and frequent co-infection of individual pigs with multiple PAstV types

2013 ◽  
Vol 94 (3) ◽  
pp. 570-582 ◽  
Author(s):  
Chao-Ting Xiao ◽  
Luis G. Giménez-Lirola ◽  
Priscilla F. Gerber ◽  
Yong-Hou Jiang ◽  
Patrick G. Halbur ◽  
...  
Keyword(s):  
Zoonotic Potential ◽  
The Novel ◽  
Extraintestinal Manifestations ◽  
Faecal Samples ◽  
High Prevalence ◽  
The Usa ◽  
History Of ◽  
Identification And Characterization ◽  
Sequence Identities

Many astrovirus (AstV) species are associated with enteric disease, although extraintestinal manifestations in mammalian and avian hosts have also been described. In this study, the prevalence rates of porcine AstV types 1–5 (PAstV1–PAstV5) were investigated using faecal samples from 509 pigs of which 488 (95.9 %) came from farms with a history of diarrhoea. All of the five known PAstV types were found to circulate in pigs in the USA, and co-infection of a single pig with two or more PAstV types was frequently observed. A high overall prevalence of 64.0 % (326/509) of PAstV RNA-positive samples was detected, with 97.2 % (317/326) of the PAstV RNA-positive pigs infected with PAstV4. Further genomic sequencing and characterization of the selected isolates revealed low sequence identities (49.2–89.0 %) with known PAstV strains, indicating novel types or genotypes of PAstV2, PAstV4 and PAstV5. Some new features of the genomes of the PAstVs were also discovered. The first complete genome of a PAstV3 isolate was obtained and showed identities of 50.5–55.3 % with mink AstV and the novel human AstVs compared with 38.4–42.7 % with other PAstV types. Phylogenetic analysis revealed that PAstV1, PAstV2 and PAstV3 were more closely related to AstVs from humans and other animals than to each other, indicating past cross-species transmission and the zoonotic potential of these PAstVs.

scholarly journals Recombination, pseudorecombination and synergism of geminiviruses are determinant keys to the epidemic of severe cassava mosaic disease in Uganda

2001 ◽  
Vol 82 (3) ◽  
pp. 655-665 ◽  
Author(s):  
J. S. Pita ◽  
V. N. Fondong ◽  
A. Sangaré ◽  
G. W. Otim-Nape ◽  
S. Ogwal ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Mosaic Disease ◽  
African Cassava Mosaic Virus ◽  
Cassava Mosaic Disease ◽  
East African ◽  
Recombinant Fragment ◽  
Complete Sequences ◽  
Natural Recombination ◽  
Cassava Mosaic Virus

The molecular variability of cassava geminiviruses occurring in Uganda was investigated in this study. Infected cassava plants and whiteflies were collected from cassava plantings in different geographical areas of the country and PCR was used for molecular characterization of the viruses. Two complete sequences of DNA-A and -B from African cassava mosaic virus (ACMV), two DNA-A sequences from East African cassava mosaic virus (EACMV), two DNA-B sequences of EACMV and the partial DNA-A nucleotide sequence of a new virus strain isolated in Uganda, EACMV-UG3, are reported here. Analysis of naturally infected cassava plants showed various assortments of DNA-A and DNA-B of the Ugandan viruses, suggesting the occurrence of natural inter- and intraspecies pseudorecombinations and a pattern of cassava mosaic disease (CMD) more complex than previously reported. EACMV-UG2 DNA-A, which contains a recombinant fragment between ACMV and EACMV-UG1 in the coat protein gene that resembles virus from Tanzania, was widespread in the country and always associated with EACMV-UG3 DNA-B, which probably resulted from another natural recombination event. Mixed infections of ACMV-UG and EACMV-UG in cassava and whiteflies were detected in most of the regions where both viruses occurred. These mixed-infected samples always showed extremely severe CMD symptoms, suggesting a synergistic interaction between ACMV-UG and EACMV-UG2. The first demonstration is provided of infectivity of EACMV clones to cassava, proving conclusively that the pseudorecombinant EACMV-UG2 DNA-A+EACMV-UG3 DNA-B is a causal agent of CMD in Uganda.

scholarly journals Mycoparasitic antagonism of a Trichoderma harzianum strain isolated from banana plants in Oaxaca, Mexico

Biotecnia ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 127-134
Author(s):  
Ana Claudia Sánchez-Espinosa ◽  
José Luis Villarruel-Ordaz ◽  
Luis David Maldonado Bonilla
Keyword(s):  
Biological Control ◽  
Developing Countries ◽  
Trichoderma Harzianum ◽  
Phytopathogenic Fungi ◽  
The Novel ◽  
Panama Disease ◽  
Banana Production ◽  
Biocontrol Potential ◽  
Identification And Characterization

Bananas are important crops in developing countries with tropical climate. In Mexico, the banana production has increased, and it must be guaranteed. The Panama disease, caused by the fungus Fusarium oxysporum f.sp. cubense threatens the current banana production, for what is necessary to implement methods to protect this crop. Fungi from genus Trichoderma are natural residents of the rhizosphere. This genus comprises mycoparasite species used to control diseases caused by phytopathogenic fungi, and also benefit plant development. In this report, we present data of the identification and characterization of the novel strain Trichoderma harzianum M110 that displays antagonism and biocontrol potential in laboratory conditions. Exploration of the rhizosphere and the endophytic microbial communities might help to identify microbes adapted to banana plants that can be incorporated in organic biological control formulations that ensure production of Fusarium-free plants and healthy fruits with export quality.

Sign in / Sign up

Export Citation Format

Share Document