Bacterial cancer prevention
Among the chronic diseases of perennial crops (grapes, fruit, berries, roses, etc.), bacterial cancer is especially dangerous, causing significant damage to the economy of farms. The disease is common in all regions of Moldova, where grapes are cultivated, fruit crops. The intensity of tumor formation is maximal in those places where plants are often damaged by low negative temperatures in winter or during frosts, and also after hail, in places of injuries (frost and hail slaughter, rupture of the periderm during root formation, mechanical damage on the sleeves and boles).
The causative agent of bacterial cancer is a pathogenic species of the genus Agrobacterium, the rod-shaped gram-negative bacterium Agrobacterium tumefaciens, which, when it enters wound sites, enters the vessels and moves throughout the plant. The danger is due to the fact that the pathogen bacterium can for a long time be in the vessels of plants in a latent (latent) form without tumors on the surface of the underground (fruit and berry crops) and above-ground (grapes) parts of plants.
The onset of tumor formation in the grapes coincides with the period of "crying" of the bushes, when a huge number of pathogenic bacteria penetrate into the wound sites. A significant part of them falls into the soil. If there is no pathogen in the vessels of the plant, then it will not enter the soil, since the bacterium is not spore-forming and cannot be transported through the air.
Over time, as a result of complex biological processes involving enzymes of the bacterial and plant cells, a portion of the bacterial gene - the Ti plasmid - is inserted into the chromosome of the plant cell, which begins to divide according to the model of tumor growth. Once an infected plant becomes chronically ill. Tumors are the result of infection and, as a rule, form 1-3 years after planting the plants in a permanent place.
The cancer-causing bacterium lives only in symbiosis with the host plant, since it must be fed with a certain composition of physiologically active substances found only in plants to maintain pathogenicity. A pathogenic bacterium does not exist without plant debris in the soil. With root secretions, it can migrate to the root surface.
There are no grape varieties resistant to bacterial cancer. In the practice of plant protection, there are no chemicals with a bactericidal effect that can penetrate deep into plant tissue without phytotoxic effects. To date, no means and methods have been developed to combat bacterial cancer due to the phytotoxicity of existing pesticides.
Modern methods of biotechnology make it possible to solve the problem of preventing and inhibiting tumor formation during infection with a pathogen of cancer. These include the biological drug paurin, created on the basis of the soil-saprophytic bacterium of the genus Pseudomonas, isolated from a natural microbial population. The products of its metabolism have antimicrobial and antitumor effects without a phytotoxic effect in relation to the host plant. The drug Paurin does not have a harmful effect on the environment, harmless to humans, animals, insects.
Pre-planting bacterization of the base of cuttings, roots of seedlings provides the preferred propagation of microorganisms in the rhizosphere of the plant - antagonists of the cancer causative agent, which prevents infection from the soil or the development of systemic (from blood vessels), latent (previously invisible) infection.