No abstract

The use of plants as bioreactors has become of a great importance in the modern biotechnology. The transgenic plants are capable of synthesizing of many substances, including valuable pharmaceuticals. Plants possess a number of advantages compared to conventional bioreactors - microorganisms and animal cell cultures. The product safety and lower production costs are among them. One of the promising directions in plant biotechnology is the creation of “edible vaccines, plantibodies and adjuvants” based on recombinant antigens, immunoglobulins and immunoregulatory cytokines. Edible bioreactor plants can be administered as food and feed additives in medicine and veterinary avoiding expensive purification procedures. Interferons have antiviral, antibacterial, antitumor and immunomodulatory activity, and are implicated in the prophylaxis and therapy of diseases of different etiologies. Investigations concerning with obtaining of bioreactor plants synthesizing γ-interferons of mammals and birds are carried out in the laboratory of genetic and cellular engineering of plants St. Petersburg State University. Our recent achievements in the creation of inbreed tobacco line producing bovine γ-interferon are described.

The genetic control of light-independent chlorophyll biosynthesis in plant cells has been investigated using Chlamydomonas reinhardtii Lts3-mutants defective in dark chlorophyll biosynthesis on the stage before protochlorophyllide to chlorophyllide conversion. In heterotrophic conditions the mutants are unable to synthesize chlorophyll and accumulate protoporphyrins, after illumination they are greening. The mutants were tested for pigment contents, activity of enzymes and expression of the genes, encoding these enzymes. The LTS3 gene has been identified by positional cloning, and the predicted LTS3 protein appeared to be a GATA transcription factor, which activate the expression of genes encoded chlorophyll biosynthesis enzymes: Mg-chelatase and glutamate 1-semialdehyde aminotransferase in the dark, and possibly, important for adaptation of plant cells for autotrophic conditions.

Protecting metal articles from corrosion is pressing in all stages of their manufacture and use. Foci of corrosion that arise during storage and shipment significantly complicate application of galvanic and paint and varnish coatings, worsen the quality, and reduce the lifetime of the articles.To eliminate these defects, mechanical treatment or chemical etching of the surface layer are included in the manufacturing process, and conservation of the articles between operations is used to prevent them. The last method is the simplest and least laborious.However, in this case, too, due to the poor compatibility of the conservation compositions and process media, process media residues must be removed from the surface of the part before they can be applied.Conservation oil (CM) used for sheet protection at metallurgical combines and in automobile plants before sending the stock for stamping is removed with a special detergent.In metalware production, the finished parts (when thermal or galvanic treatment is not planned) are carefully degreased with detergent solutions before going to the conservation oil bath. The effectiveness of the anticorrosion protection is a function of the quality of degreasing and the corrosiveness of the detergent solution to a significant degree.Such a combination of mechanical treatment and conservation of metal parts and stock is typical of most machine-building plants. For this reason, developing conservation-process lubricants (CPL) that allow combining these operations and eliminating the stage of intermediate degreasing is pressing.The CO manufactured in Russia cannot be used in even the simplest metal-working operations where low-efficiency process lubricants (PL) or ordinary industrial oils are used as process media. The mandatory requirements for PL are: simplicity of removal from the surface of the metal, ease of application, and stability during prolonged storage. The currently offered PL and protective materials are usually either highly viscous, which makes it difficult or impossible to feed them into the treatment zone or are not completely removed from the surface of the metal by the detergents used in machine building.

Many of the most modern drugs are of a protein nature and are synthesized by transgenic producer organisms. Bacteria, yeast, or animal cell cultures are commonly used, but plants have a number of advantages—minimal biomass unit cost, animal safety (plants are not attacked by mammalian pathogens), the agricultural scale of production, and the ability to produce complex proteins. A disadvantage of plants may be an unstable level of transgene expression, which depends on the transgene structure and its insertion site. We analyzed the structure of T-DNA inserts in transgenic tobacco plants (Nicotiana tabacum L.) belonging to two lines obtained using the same genetic construct but demonstrating different biological activities of the recombinant protein (bovine interferon-gamma). We found that, in one case, T-DNA was integrated into genomic DNA in the region of centromeric repeats, and in the other, into a transcriptionally active region of the genome. It was also found that in one case, the insert has a clustered structure and consists of three copies. Thus, the structure of T-DNA inserts in both lines is not optimal (the optimal structure includes a single copy of the insert located in the active region of the genome). It is desirable to carry out such studies at the early stages of transgenic plants selection.