[Phylogenetic Analysis of Ukrainian Isolate of Beet Necrotic Yellow Vein Virus].

The analysis of Ukrainian isolate of beet necrotic yellow vein virus has been performed. The partial nucleotide sequence of cDNA corresponding to RNA-2 of BNYVV isolates were analyzed and Ukrainian isolate AG9 of BNYVV was assigned to type A strains based on DNA sequences. The nucleotide sequence of gene encoding a coat protein of Ukrainian isolate of BNYVV was compared with appropriate nucleotide sequences existing in the GeneBank and the phylogenetic analysis of investigated virus was done. It was shown that Ukrainian isolate AG9 of BNYVV has 100 % homology to isolate originating from Sweden.

[Influence of bean yellow mosaic virus on metabolism of photosynthetic pigments, proteins and carbohydrates in Glycine soja L].

This paper presents data on BYMV effects on some physiological processes of Glycine soja L. cultivated in the right-bank forest-steppe regions. Pigment content (chlorophyll a, b and carotenoids), soluble proteins and water soluble carbohydrates were estimated and, as has been shown, are subjected to significant changes as compared with control plants, namely: a decrease in the content of chlorophyll a, b and carotenoids was 64%, 53% and 36% compared with the control plants. The significant increase in carbohydrates (56% compared to the control) was observed at the end of the test period.

[Codon bias and nucleotide substitutions in soybean dwarf virus].

Computational analysis of codon usage bias and spontaneous nucleotide substitutions in six strains of soybean dwarf virus was performed. It was shown that synonymous codon usage in the virus genes varies widely depending on the gene, gene overlapping, codon, codon's two first nucleotides, mononucleotide context located upstream and downstream of the codon, GC-content in virus-encoded genes and in the third codon position. Overlapping of genes causes a 2.5-fold decrease of the total number of nucleotide substitutions, 2.8-4.3-fold decrease of the number of synonymous substitutions in the third codon position, 1.4-1.6-fold decrease of the dicodon content in genes. At the same time there is a significant increase of nonsynonymous substitutions in the second codon position as well as a high codon bias (Fop = 0.94-1.0) and correlation between the nucleotide content in genes and in the third codon positions (r = 0.73-0.74). The results obtained evidence for selection of dicodons in the viral genes.

Biological characteristic and identification of soybean virus isolated from different Ukraine regions.

To examine the presence and level of viral infection, field observations of the soybean crops in the Cherkassy, Vinnitsa and Kyiv regions have been performed. It was established that the diseases in the soybean plants growing in the examined areas have been caused by two major viruses--SMV (Soybean mosaic virus) and BYMV (Bean yellow mosaic virus). The results of field observations have been confirmed using light and electron microscopy and ELISA.

[Spontaneous nucleotide substitution in potato virus X genes].

Elucidation of the factors underlying nucleotide substitution types and rates in genomes is of significance for improving the prevalent models for molecular evolution, and is essential in studying the evolution process, distinguishing the coding and noncoding RNAs, identifying biologically significant motifs such as replication signals, control regions and so on. However, many questions concerning the factors that affect the nucleotide substitutions in plant virus genomes still remain unclear. In this paper a comparative computer analysis of nucleotide substitution in genomic sequences of 10 pairs of closely related potato virus X (PVX) strains having equal genome and gene length has been carried out. A significant frequency variation of nucleotide substitutions, depending on nucleotide and strain pairs, length and localization of genome and gene regions as well as substitution types and their codon positions, was found. The highest relations of substitution frequency are found in different nucleotide pairs (u-->c/c-->g, 1240), codon positions (third/second, 17.3) and substitution types (transitions/transversions, 5.8), the least ones - in forward and back substitutions in the same nucleotide pairs (1.03-1.6). The transversion frequencies are generally significantly lower but more variable than the transition one, and there is no direct relationship between gene (region) length and transversion frequency.

[Genetic bases and functioning of plant signal transduction at virus resistance].

Recent insights into virus-host interaction have been compiled in this review, focusing on the genetic basis and the modern conception of the molecular mechanisms of pathogen (mostly viral) recognition by plants. The significance of plant signal transduction systems and their key factors are discussed. The possible role of different elicitors in signal transduction processes has been considered.

[Genetically programmed cell death: the basis of homeostasis and form of phytoimmunity response].

This paper gives a brief overview of the recent ideas about programmed cell death including apoptosis in animals and plants. Comparison of these processes in animal and plant cells in terms of physiological features has been presented. Necrosis as a form of pathological, not genetically programmed cell death has been characterized. Reflections about the meaning (the need) of apoptosis in the formation of hypersensitive response in plants and the role of programmed cell death in joint relations between pathogens and plants have been considered.

[Molecular-genetic mechanisms of plant resistance to viruses].

This paper gives a brief overview of the recent ideas about molecular and genetic mechanisms of plant resistance to viruses. Two plant antiviral strategies (R-gene-mediated mechanism and RNA-silencing) are considered. Examples of engineered virus resistance are presented.

[Conservative nucleotide sites in promoters of tobamoviral subgenomic RNA].

A computer search for position-linked identical nucleotide sites in sequences of promoter regions of subgenomic RNA and coat protein of fifteen tobamoviruses was performed. It was discovered that promoters of three TMV strains tested as well as of tobacco mild green mosaic virus and turnip vein-clearing virus contain the nine-nucleotide sites gattcgttt or ggttcgttt. These sites are localized at 14-77 nucleotide upstream from the translation start codons of coat or movement protein genes and are flanged with length-variable gc- (upstream) and at-containing sequences (downstream). The middle part of the nine-nucleotide sites (tcgtt) is present in 22 of 30 promoter regions tested. The role of the conservative sites found as functional elements of tobamoviral subgenomic RNA promoters is discussed.

[TMV-infection localization and development of induced virus resistance in Nicotiana sanderae Hort., Datura stramonium L. and Datura metel]. / Lokalizatsiia VTM-infektsiï i rozvytok indukovanoï stiikosti u Nicotiana sanderae HORT., Datura stramonium L. ta Datura metel L.

The localization of virus infection and development of local and systemic induced resistance in plants Nicotiana sanderae Hort., Datura stramonium L. and D. metel L. infected by TMV have been studied. It was shown that acquired resistance to the second infection is induced in hypersensitive plants infected by TMV independent of localization mechanism. No definite correlation exists between these defense reactions.

[Effect of TMV-infection on protein and carbohydrate content in hypersensitive tobacco plants and their antiviral and hemagglutinating activity]. / Vplyv VTM-infektsiï na vmist bilkiv i vuhlevodiv u nadchutlyvykh roslynakh tiutiunu ta ïkhniu antyvirusnu i hemahliutynuval'nu aktyvnist'.

Changes in content of proteins and carbohydrates of sensitive and supersensitive tobacco and datura plants and their antiviral and hemagglutinating activity under tobacco mosaic virus infection were investigated. It was shown that the content of these substances was increased on early stages of virus infection in hypersensitive plants. Antiviral and hemagglutinating activity of the obtained substances was shown.