Delivery of CRISPR/Cas Components into Higher Plant Cells for Genome Editing

Russian Journal of Plant Physiology - CRISPR/Cas genome editing of plants is realized in three basic variants, including knockout mutations as indels, insertion of alien DNA fragments, and base...     

Protective Effect of Arachidonic Acid during Viral Infection: Synthesis of New Proteins by in vitroPotato Plants

The mechanisms of the protective, immunostimulating effects of arachidonic acid (AA) were studied, and its efficiency in the induction of defense reactions in the moderately virus-resistant potato cultivar Nevskii (Solanum tuberosumL.) was determined. Virus-free in vitropotato plants treated with AA and inoculated with phytopathogenic viruses were used as a model. The data on the X virus accumulation obtained by the enzyme-linked immunosorbent assay confirmed the immunizing effect of AA; the optimum concentration of the compound was 10^–8M. The antiviral effect of AA was maintained in infected in vitropotato plants for at least two or three weeks. The electrophoretic analysis of leaf proteins revealed a 33-kD polypeptide induced by the potato virus Y. Two weeks after inoculation with virus X, a 40-kD protein was identified in potato plants pretreated with AA. In addition, the relative content of the two groups of proteins consisting of two or three components with mol wts about 50 kD and above70 kD changed both upon viral infection and pretreatment with AA. Only small changes in the isozyme patterns of peroxidase in potato plants were observed during the development of systemic acquired resistance; they were manifested in some treatments in the band intensities. The existence of the alternative pathways of systemic acquired resistance in potato plants specifically activated by viral infection and AA was suggested.     

Evaluation of the possibility of using genetic and microbiological research methods for resolving current problems in the epidemiology of salmonellosis

S. typhimurium strains isolated in 14 regions of the USSR have, parallel with considerable similarity in their biological characteristics, a number of essential differences. These differences become manifest in the determination of the plasmid spectra of the above organisms. The transfer of R-plasmid PLE518 F1 me fin+ with a molecular weight of 96 Md to strains, sensitive to the action of typing bacteriophages, renders these strains resistant to the lytic action of a number of phages, which leads to the conversion of their phage type. In some cases it may deteriorate the validity of the method of phage typing, used for epidemiological purposes.     

Hormonal status of tobacco variety Samsun NN exposed to synthetic coenzyme Q10 (ubiquinone 50) and TMV infection

Hormonal system status has been analyzed in leaf disks of hypersensitive tobacco Nicotiana tabacum L. variety Samsun NN during the development of resistance to tobacco mosaic virus (TMV) induced by synthetic coenzyme Q₁₀ (ubiquinone 50). The absolute and relative content of abscisic acid (ABA), indoleacetic acid (IAA), and cytokinins (CKs) was determined after the exposure of leaves to Q₁₀ solution and the subsequent TMV infection. In plants not treated with Q₁₀, CK content increased about 2.5 times 1 day after TMV infection, while a significant increase in the ABA level and a decrease in the IAA level were observed only after 2 days. In the dynamics, Q₁₀ treatment had a protective antiviral effect, significantly decreased the ABA level, and increased the IAA level in sensitized plants compared to nonsensitized ones.     

RAPD-PCR analysis of the variability of spring common wheat cultivar genomes and their androclinal double haploid form

Based on RAPD-PCR analysis with 15 primers including those homologous to particular loci, the level of genetic polymorphism in the collection of spring common wheat genotypes and their androclinal double haploid (ADH) lines was determined. Intraspecific polymorphism of the original wheat forms was 20%. By the absence of polymorphism in the molecular patterns of ADH lines and original forms, it was shown that, under the conditions used, no genetic changes in the genomic DNA of spring common wheat in anther culture occurred. Thus, the technology of direct in vitro androgenesis does not lead to genome rearrangements and may be used for rapid production of pure lines of such a complex allopolyploid as spring common wheat.     

Incidence of antibiotic resistance in Salmonella typhimurium strains isolated in different epidemic situations

A total of 1800 S. typhimurium strains isolated in different regions of the USSR in 1968-1979 were studied. Of these strains, 68.6% were resistant to 6-8 antibiotics, 7.8% were resistant to 2-5 antibiotics, and 23.6% proved to be resistant to all antibiotics. The number of multiresistant strains sharply increased during the last 10 years. The strains isolated from different sources and in different epidemic situations considerably differed in their sensitivity to the action of antibiotics. The infective agents isolated from the hospital foci of salmonellosis were found to possess the maximum multiresistance. The study of the genetic nature of multiresistance showed that the multiresistance strains had a conjugative R-plasmid with resistance determinants CmTc, type Fin+, incompatibility group F1me. The phage typing of the strains with phages from the collection of the Tbilisi Research Institute for Vaccines and Sera revealed that these strains belonged to phagotype 2. The problems of the relationship between the biological properties of causative agents and the character of the epidemic process of the diseases caused by these agents are discussed.     

Etiological structure of salmonellosis and the serotype passage of salmonellae isolated in separate regions of the USSR in 1980-1982

At the period of 1980-1982 the isolation of salmonellae belonging to 394 serovars was registered in the USSR. Of these, 116 Salmonella serovars were registered in the USSR for the first time. 12 dominating serovars constituted 83.1% of salmonellae isolated from humans, 99% of salmonellae isolated from animals and 70% of all salmonellae isolated from different environmental objects. S. typhimurium was the predominant serovar, found to determine 50% of cases of Salmonella infection. The isolation rate of S. infantis and S. virchow was shown to increase. The existence of definite ecological relationships between infective agents isolated from different sources was established.     

Induction of Phytohemagglutinin Activity by Arachidonic Acid in in vitro Potato Plants

Tube-grown potato (Solanum tuberosum L., cv. Nevskii) plants treated with arachidonic acid (AA) were used as a model to study the activity of phytohemagglutinins (PHA) during induction of the plant antiviral defense system. Plant treatment with 10^–8 M AA and also their inoculation with potato viruses X, Y, and M resulted in the increased activity of PHAs in potato shoots. The inducer of antiviral resistance behaved as a modulator of the PHA activity providing for its various levels during the development of viral infection. During the development of AA-induced systemic resistance, the level of phytohemagglutinin activity did not essentially depend on the nature of the viral pathogen. We suggested that the mechanism of AA-induced plant antiviral defense was connected with changes in the PHA activity.     

Chemico-enzymatic synthesis of Salmonella newington O-specific polysaccharide and its modified derivatives

Treatment of the DMan (beta 1-4) LRha (alpha 1-3) D [3H]Gal-derivative of moraprenyl pyrophosphate with the cell envelope preparation from S. newington results in the formation of polysaccharide with beta 1-6 linkage between the trisaccharide units (polymerization degree approximately 8). The synthetic derivatives of moraprenyl pyrophosphate which contain D-talose, 4-deoxy-D-xylo-hexose, LRha (alpha 1-3) DGlc or LRha (alpha 1-3) DGlc (alpha 1-6) DGal were found to serve as substrates for the biosynthesis of the corresponding modified polysaccharides.