The Effect of Chitosan Conjugates with Hydroxycinnamic Acids and Bacillussubtilis Bacteria on the Activity of Protective Proteins and Resistance of Potato Plants to Phytophthora infestans.

The effect of chitosan conjugates with caffeic (ChCA) and ferulic (ChFA) acids in combination with Bacillus subtilis bacteria on the transcriptional activity of PR protein genes and proteome changes in potato plants during infection with Phytophthora infestans (Mont.) de Bary was studied. Plants grown from mini tubers of the Udacha variety were sprayed with solutions of ChCA and ChFA, a suspension of B. subtilis bacteria strains 26D and 11 VM, and conjugates of ChCA of ChFA together with bacteria. At 3 days after treatment, some plants were infected with P. infestans. A decrease in the degree of development of the late blight pathogen on potato leaves in all treatment options was revealed. The maximum protective effect was manifested when plants were treated with the B. subtilis strain 26D bacteria in combination with conjugates of chitosan and oxycinnamic acids. The mechanisms of increasing the resistance of potato plants to P. infestans were associated with the activation of transcriptional activity of genes encoding the main protective protein (PR-1), chitinase (PR-3), thaumatin-like protein (PR-5), protease inhibitor (PR-6), peroxidase (PR-9), and ribonuclease (PR-10). The revealed activation of the expression of marker genes of systemic acquired resistance and induced systemic resistance under the influence of joint treatment of plants with B. subtilis and chitin conjugates with hydroxycinnamic acids indicates the synergistic development of protective reactions in potato plants in this variant. Using the method of two-dimensional electrophoresis of S. tuberosum leaf proteins followed by MALDI-TOF analysis 12 proteins were identified; their presence in the leaves differed depending on the variant of the experiment. In all treatment variants, serine–threonine protein phosphatase activity was suppressed, reflecting the development of the hypersensitivity reaction. Different variants of the experiment formed weakly expressed clusters, which indicates multiple mechanisms of regulation of the synthesis of protective proteins involved in the reaction to treatment with bacteria, chitosan conjugates, and infection with P. infestans. [ABSTRACT FROM AUTHOR]