Sat-RNA is one of several replicating satellite RNAs which have been isolated from RNA encapsidated in cucumber mosaic virus (CMV) and which are totally dependent on CMV for replication. The 336 residue sequence of Sat-RNA obtained using the dideoxynucleotide chain termination and partial enzymic digestion procedures shows only a few short stretches (up to 11 residues) of sequence homology with...

Knowing how hosts respond to parasite infection is paramount in understanding the effects of parasites on host populations and hence host-parasite co-evolution. Modification of life-history traits in response to parasitism has received less attention than other defence strategies. Life-history theory predicts that parasitised hosts will increase reproductive effort and accelerate reproduction. ...

BACKGROUND Heteronucleophiles as well as carbanionic reagents can be used to react with α-amido sulfones, thus giving the opportunity to prepare a large array of amino derivatives. Since, novel 1,3,4-oxadiazole-2-thiol derivatives can serve as potent nucleophiles, we employed 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the nucleophilic source of nitrogen in the reaction with α-amido sulfo...

The Rx locus in potato controls extreme resistance to most isolates of potato virus X (PVX). The resistance is expressed in whole plants and in protoplasts. Rx-mediated resistance in protoplasts causes reduced accumulation of all PVX RNA species, including the (-) strand RNA after a lag of 8 hr postinoculation. In work reported elsewhere, we have shown that the Rx-breaking property of PVXHB was...

Plant viruses elicit the expression of common sets of genes in susceptible hosts. Studies in Arabidopsis (Arabidopsis thaliana) and tomato (Lycopersicon esculentum) indicate that at least one-third of the genes induced in common by viruses have been previously associated with plant defense and stress responses. The genetic and molecular requirements for the induction of these stress and defense...

virus infections are a major limiting factor in cucurbit production in iran. cucumber green mottle mosaic virus (cgmmv) infects many cucurbit species in the world and causing mottle and systemic mosaic symptoms on cucurbitaceous plant leaves. during 2008-2009, from different cucurbitaceous species fields and cucumber greenhouses in razavi and northern khorasan provinces, 220 leaf samples with c...

Virus-resistant transgenic plants have been created primarily through the expression of viral sequences. It has been hypothesized that recombination between the viral transgene mRNA and the RNA of an infecting virus could generate novel viruses. As mRNA/viral RNA recombination can occur in virus-resistant transgenic plants, the key to testing this risk hypothesis is to compare the populations o...

The Cucumber mosaic virus (CMV) 2b protein is a counter-defense factor and symptom determinant. Conserved domains in the 2b protein sequence were mutated in the 2b gene of strain Fny-CMV. The effects of these mutations were assessed by infection of Nicotiana tabacum, N. benthamiana, and Arabidopsis thaliana (ecotype Col-0) with mutant viruses and by expression of mutant 2b transgenes in A. thal...

The structure and genetic diversity of a California Cucumber mosaic virus (CMV) population was assessed by single-strand conformation polymorphism and nucleotide sequence analyses of genomic regions 2b, CP, MP, and the 3' nontranslated region of RNA3. The California CMV population exhibited low genetic diversity and was composed of one to three predominant haplotypes and a large number of minor...