Effect of Endophytic Bacteria Bacillus subtilis on Components of the Pro-/Antioxidant System of Tomato Plants (Solanum lycopersicum L.) Infected with Potato Viruses X and Y

Currently, the most promising and environmentally friendly method of combating viral diseases is considered to be the use of plant growth promoting bacteria (PGPB) and their metabolites, which can exhibit both direct antiviral activity and stimulate the defense mechanisms of host plants. In this work, the ability of endophytic bacteria Bacillus subtilis (Cohn.) strains 26D and Ttl2 to suppress the reproduction of potato virus Y (PVY) and potato virus X (PVX) on tomato plants (Solanum lycopersicum L.) and to stimulate the growth of infected plants by regulating the redox balance was discovered. Bacterial strains B. subtilis 26D and B. subtilis Ttl2 reduced the titer of PVY and PVX in tomato plants, restored their growth to control values, which was accompanied by a decrease in symptoms and severity of the disease. PVY and PVX disrupted the redox status of plants for their development. Bacterial strains B. subtilis 26D and B. subtilis Ttl2 regulated the generation of hydrogen peroxide by changing the activity of catalase and positively affected the activity of peroxidases of tomato plants infected with PVY or PVX, which suggests the possibility of using these strains as a basis for creating an antiviral biocontrol agent.