scholarly journals Effect of the Host and Temperature on the Formation of Defective RNAs Associated with Broad bean mottle virus Infection

2004 ◽  
Vol 94 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Susana Llamas ◽  
Claudio Sandoval ◽  
Mar Babin ◽  
Judy Pogany ◽  
Jozef J. Bujarski ◽  
...  
Keyword(s):  
De Novo ◽  
Broad Bean ◽  
Chenopodium Quinoa ◽  
Mottle Virus ◽  
First Passage ◽  
Defective Rnas ◽  
Bean Plants ◽  
Rna Accumulation ◽  
Broad Bean Mottle Virus ◽  
Nicotiana Clevelandii

Previously, we demonstrated that Broad bean mottle virus (BBMV), a member of the genus Bromovirus, could accumulate RNA 2-derived defective interfering (DI) RNAs during infection. In this work, we study how host and environmental factors affect the accumulation of DI RNAs. Serial passages of BBMV through selected plant species reveal that, with low-multiplicity inocula, some systemic hosts (Vicia faba, Nicotiana clevelandii, and N. tabacum cv. Samsum) support DI RNA accumulation after the first passage cycle but other hosts (Phaseolus vulgaris, Pisum sativum, and Glycine max) do not. However, several passages with the high-multiplicity inocula can generate DI RNAs in pea plants. Local lesion hosts (Chenopodium quinoa, C. amaranticolor, and C. murale) remain free of the DI RNA components. The size of the de novo-formed DI RNAs depends on the host and on environmental conditions. For instance, broad bean plants cultivated in a greenhouse or in a growth chamber at 20°C accumulated DI RNAs of 2.4 or 1.9 kb in size, respectively. A reverse trend was observed in pea plants. Lower temperatures greatly facilitated the formation of DI RNAs in broad bean and pea hosts after the first passage. The importance of these findings for the studies on DI RNAs are discussed.

scholarly journals In Vitro- and In Vivo-Generated Defective RNAs of Satellite Panicum Mosaic Virus Define cis-Acting RNA Elements Required for Replication and Movement

2000 ◽  
Vol 74 (5) ◽  
pp. 2247-2254 ◽  
Author(s):  
Wenping Qiu ◽  
Scholthof G. Karen-Beth
Keyword(s):  
Mosaic Virus ◽  
De Novo ◽  
Stop Codon ◽  
Dependent Manner ◽  
Defective Rnas ◽  
Systemic Spread ◽  
Rna Elements ◽  
Rna Domains ◽  
Rna Accumulation

ABSTRACT Satellite panicum mosaic virus (SPMV) depends on its helper virus, panicum mosaic virus (PMV), to provide trans-acting proteins for replication and movement. The 824-nucleotide (nt) genome of SPMV possesses an open reading frame encoding a 17.5-kDa capsid protein (CP), which is shown to be dispensable for SPMV replication. To localize cis-acting RNA elements required for replication and movement, a comprehensive set of SPMV cDNA deletion mutants was generated. The results showed that the 263-nt 3′ untranslated region (UTR) plus 73 nt upstream of the CP stop codon and the first 16 nt in the 5′ UTR are required for SPMV RNA amplification and/or systemic spread. A region from nt 17 to 67 within the 5′ UTR may have an accessory role in RNA accumulation, and a fragment bracketing nt 68 to 104 appears to be involved in the systemic movement of SPMV RNA in a host-dependent manner. Unexpectedly, defective RNAs (D-RNAs) accumulated de novo in millet plants coinfected with PMV and either of two SPMV mutants: SPMV-91, which is incapable of expressing the 17.5-kDa CP, and SPMV-GUG, which expresses low levels of the 17.5-kDa CP. The D-RNA derived from SPMV-91 was isolated from infected plants and used as a template to generate a cDNA clone. RNA transcripts derived from this 399-nt cDNA replicated and moved in millet plants coinoculated with PMV. The characterization of this D-RNA provided a biological confirmation that the critical RNA domains identified by the reverse genetic strategy are essential for SPMV replication and movement. The results additionally suggest that a potential “trigger” for spontaneous D-RNA accumulation may be associated with the absence or reduced accumulation of the 17.5-kDa SPMV CP. This represents the first report of a D-RNA associated with a satellite virus.

Vergleich zwischen Eigenschaften des Echten Ackerbohnenmosaik-Virus und des broad bean mottle-Virus

1960 ◽  
Vol 15 (7) ◽  
pp. 444-447 ◽  
Author(s):  
C. Wetter ◽  
H. L. Paul ◽  
J. Brandes ◽  
L. Quantz
Keyword(s):  
Nucleic Acid ◽  
Acid Content ◽  
Thermal Inactivation ◽  
Broad Bean ◽  
Seed Transmission ◽  
Mottle Virus ◽  
Nucleic Acid Content ◽  
Thermal Inactivation Point ◽  
Broad Bean Mottle Virus ◽  
Point Seed

Broad bean true mosaic virus (EAMV) has been studied in comparison with broad bean mottle virus (BBMV), after both viruses had been purified by the same procedure. Spectrophotometric and/or chemical determinations revealed a nucleic acid content of 32% for EAMV and 23% for BBMV. Serologically, the two viruses are unrelated since in reciprocal testings they react with their homologous antisera only. The diameter of of the particles has been determined to 25 mμ for EAMV and 20 mμ for BBMV. Further differences include thermal inactivation point, seed transmission, host range, and symptomatology.There are no indications for a relationship among both viruses as suggested in the list of Common names (Review of Applied Mycology, Vol. 35, Suppl.).

Physikalische und chemische Untersuchungen am broad bean mottle-Virus

1961 ◽  
Vol 16 (12) ◽  
pp. 786-791 ◽  
Author(s):  
H. L. Paul
Keyword(s):  
Molecular Weight ◽  
Broad Bean ◽  
Uv Light ◽  
Diffusion Constant ◽  
Aromatic Amino Acids ◽  
Mottle Virus ◽  
Partial Specific Volume ◽  
Absorption Data ◽  
Broad Bean Mottle Virus ◽  
Maximum Turbidity

Broad bean mottle virus (BBMV) contains 15.2 percent N and 1.83 percent P; the N/P ratio is 8.4 ± 0.3. The protein of BBMV contains 15.6 percent N and no P; the NA has a N/P ratio of about 1.85. From these data a NA content of about 22 percent can be evaluated. This value agrees with that of 23 percent obtained by orcinol reactions.The sedimentation constant at infinite dilution is 83 ± 2 S, the diffusion constant 1.44 ± 0.04 · 10-7 cm2/sec, and the partial specific volume 0.75 cm3/gram. From these data a molecular weight of 5.6 ± 0.5 millions for the unhydrated particles can be calculated. The diameter of these particles is about 24 mµ, which agrees fairly well with determinations made with the electron microscope 1. Estimations of molecular weight and diameter of the hydrated particles reveal about 10 millions and about 30 mu respectively.Purified BBMV was stable in neutral buffer solutions at 3 °C for some weeks and remained infective. Exhaustive dialysis of such virus suspensions against dist. water caused a considerable increase in turbidity, and, later on, precipitation of the virus. It was not possible to resuspend this virus completely by adding neutral buffer or salt solutions. Density gradient centrifugations showed these resuspensions to be inhomogeneous, whereas non-dialyzed virus suspensions in buffer gave only one narrow zone in the gradient tubes, indicating the homogeneity of the particles.In buffers of different pH , virus suspensions showed a maximum turbidity at about pH 4.5. For precipitations of BBMV with ammonium sulfate, higher salt concentrations were necessary than for most other viruses.The UV light absorption (corrected for light scattering) of BBMV as well as of its protein and its NA was measured. It could be shown that the absorption coefficient of BBMV protein is much lower than that of most other viruses, presumably because of the low content of aromatic amino acids as determined by chemical analysis recently 2.The estimation of the NA content of BBMV from UV absorption data is discussed.

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