Bermuda Grass as a Potential Reservoir Host for Grapevine fanleaf virus.

Grapevine fanleaf virus (GFLV) was detected in samples of Bermuda grass (BG) from Iran by reverse transcription-polymerase chain reaction (RT-PCR) using two different pairs of GFLV-specific primers, and also by enzyme-linked immunosorbent assay (ELISA) using antiserum specific for a North American isolate of the virus. RT-PCR detected GFLV in both fresh and dried BG tissues and in virus preparations purified from these plants. Cloning and sequencing of the RT-PCR products confirmed that the amplified sequences were sections of the GFLV coat protein gene. Similar results were obtained when random and oligo(dT) primers were used on viral RNA templates recovered from BG to synthesize cDNA for cloning and sequencing. The virus induced few or no symptoms in BG, but could nonetheless be transmitted from BG to Chenopodium quinoa by mechanical inoculation. Some isolates induced systemic chlorotic spots and leaf deformation; others remained symptomless in this plant. Both symptomatic and symptomless C. quinoa plants were found to be infected with GFLV, giving positive ELISA and RT-PCR tests. A North American isolate of GFLV was found to be mechanically transmissible to BG as indicated by positive RT-PCR results from root samples of inoculated plants. GFLV-infected BG was widely distributed in the Fars province of Iran.

The detection of fake-bad and fake-good responding on the Millon Clinical Multiaxial Inventory III.

The purpose of this study was to examine the effectiveness of the 3 Modifying Indices of the Millon Clinical Multiaxial Inventory III (MCMI-III) in the detection of fake-bad and fake-good responding. The sample consisted of 160 psychiatric outpatients. Paired t tests were performed to examine the effects of instructional set (faking vs. standard instructions). As hypothesized, instructional set produced significant differences on Scale X, Scale Y, and Scale Z in both fake-bad and fake-good analyses. Single-scale cutoff scores were as effective as multiple-scale cutoffs. The overall rates of successful classification indicated moderate effectiveness and utility of the MCMI-III Modifying Indices in the detection of dissimulated responding. When base rates were varied to more closely approximate a general clinical population, overall classification accuracy increased, but identification of faking (positive predictive power) gradually eroded with declining base-rate estimates. At lower base rates of faking, MCMI-III standard cutoff points yielded a high number of false positives.

Gene I products of cauliflower mosaic virus detected in extracts of infected tissue.

The product of cauliflower mosaic virus (CaMV) gene I has been characterized from extracts of infected plants. Two size classes of this protein can be identified by the use of specific antiserum. The antiserum was induced against a chimeric protein produced in E. coli from a gene fusion between a fragment of the CaMV genome and the beta-galactosidase gene. A 36-kDa form of the gene I product is associated with virus particles. A 45-kDa form of this product was found only in the insoluble fraction of tissue homogenates. This insoluble fraction, the only fraction found to contain the product of viral gene VI, contains the virally induced inclusion bodies.

Expression of disease symptoms in cauliflower mosaic virus genomic hybrids.

In an effort to determine if particular regions of the cauliflower mosaic virus (CaMV) genome could be associated with particular phenotypic characters, strains of CaMV differing markedly in biological properties were recombined to produce hybrids. DNA from pairs of (infectious) genomic clones was cleaved with restriction endonucleases, then mixed and ligated. Recombinants were found by screening transformants in E. coli, or by selection in vivo for infectious hybrids. Recombinants in infected turnip plants were characterized by restriction endonuclease mapping of their DNA to confirm the hybrid genotype. New hybrid strains that induced less severe disease, or conversely, more severe disease than either parent were observed. The experiments revealed that typical disease expression, consisting of leaf chlorosis and mottling, mapped to a genome segment containing open reading frame VI (ORF VI) and the full-length promoter. This basic disease symptom was found to be influenced by other regions of the genome. Insect transmissibility mapped to ORF II. The ability to develop generalized infections in solanaceous plants was tested in hybrids between CaMV CM1841 and a variant that infects Datura stramonium systemically. In this case the systemic mobilization of virus appeared to be controlled by ORF VI, suggesting that this gene may function in cell-to-cell movement of virus.

Multimeric forms of satellite of tobacco ringspot virus RNA.

An approximately 350-nucleotide residue RNA replicates in association with tobacco ringspot virus (TobRV) and becomes encapsidated in TobRV coat protein. Here we show by electrophoretic analyses that this small satellite RNA, RNA S, is the most abundant and most rapidly migrating of a series of at least ten encapsidated RNAs with RNA S sequences. A largely double-stranded RNA fraction from infected tissue, when denatured, gave a similar series of up to 12 zones that contained both RNA S sequences and sequences that hybridized to RNA S. Analysis of the mobilities suggests a weight increment between each zone corresponding approximately to the size of RNA S. Thus the more slowly migrating zones appear to contain covalent multimers of RNA S or, for tissue RNA, both multimers of RNA S and multimers of the complement of RNA S sequences. Neither terminal structure of TobRV genomic RNAs was found in the satellite RNA. RNA S lacks detectable polyadenylate or oligoadenylate. Covalently linked protein was not detected in RNA S or its more slowly migrating forms, and satellite RNA biological activity, unlike that of the TobRV RNAs, was not protease sensitive. Polynucleotide kinase catalyzed the phosphorylation of satellite RNAs, indicating free 5'-hydroxyl groups.

Genome-associated proteins of comoviruses.

Previously, a protein has been reported to be associated with the RNAs of cowpea mosaic virus. Here we present evidence for genome-associated proteins of other comoviruses: squash mosaic virus, Echtes Ackerbohnemosaik-Virus, and another strain of cowpea mosaic virus. Although the proteins and protein-oligonucleotide complexes derived from the RNAs of these viruses showed similar patterns of electrophoretic mobility, two-dimensional chromatograms of their tryptic peptides were distinct. Chromatograms of peptides from preparations of cowpea mosaic virus that were isolated from two hosts were very similar, indicating that the genome-associated protein may be virus specified. Upon digestion with ribonuclease T1, RNAs from the viruses gave rise to a distribution of large oligonucleotides that is consistent with the presence of polyriboadenylate.