PR-Proteins Accumulation in Tomato Plant Due to Application of Resistance Inducing Chemicals During Period of Induced Resistance Against Alternaria Leaf Blight

Abstract

Background: Resistance Inducing Chemicals (RIC) viz., Salicylic Acid (SA), $-aminobutyric acid (BABA), chitosan (CHT) and 2, 6-dichloroisonicotinic acid (INA) are known to play an important role in induction of resistance by increasing the activity of PR-proteins. Therefore the study was done to test these RIC's for accumulation of PR-proteins in tomato plant to confer resistance against Alternaria blight disease. Methods: The activity of PR-proteins viz., chitinase and $ 1,3-glucanase in tomato leaves were measured in response to treatment of these RIC's at different concentrations as seed dip treatment for 8 h, seedling dip treatment for 2 h and seed+seedling treatment. The RIC treated plants were challenged inoculated with Alternaria alternata, a tomato leaf blight pathogen at 10 days interval from germination and observed for disease development. Chitinases and $ 1,3-glucanase activity was determined spectronically by quantifying the release of mg of N-acetylglucosamine and of glucose, respectively at 30 days of RIC treatment as the persistence of resistance induced by RIC was up to 50 days. Results: Maximum activity of chitinase and $ 1,3-glucanase was observed in seed+seedling treatment with BABA at 15 mM concentration and the increase in chitinase and $ 1,3-glucanase activity was 32.00 and 56.59% more, respectively over control and was followed by treatment with salicylic acid at 1.5 mM concentration. Conclusion: The application of RIC SA and BABA elicits the increased activity of PR-proteins viz., chitinase and $ 1,3-glucanase which inhibit the process of pathogenesis in susceptible tomato cultivars to exhibit the resistance.

Comparative Analyses of Four Chemicals Used to Control Black Mold Disease in Tomato and Its Effects on Defense Signaling Pathways, Productivity and Quality Traits

“…The obtained results could be interpreted in light of the findings of [ 65 ], who reported that salicylic acid caused the accumulation of chitinase in tomato plants, which conferred resistance against Phytophthora infestans . On other hand, the application of SA increased the activity of PR-proteins such as chitinase and β 1,3-glucanase, which inhibited the process of pathogenesis in susceptible tomato cultivars to exhibit the resistance [ 66 ] These results also conform with the findings of [ 67 ], who observed that the treatment of grapevine leaves with chitosan resulted in a marked increase in chitinase activities, which in turn might improve the resistance to grey mold. On the other hand, chitosan treatment can induce plant defense through the stimulation of enzymes related to pathogenesis and prolong the shelf life of fruits and vegetables [ 68 ].…”

The impact of microbes in the orchestration of plants’ resistance to biotic stress: a disease management approach

“…This is to encourage the production of antimicrobial substances that will impede the proliferation of the pathogen (Hammerschmidt, 1999 ). Exogenous application of synthetic salicylic acid and beta aminobutyric acid (in a concentration of 1.5 and 15 mM, respectively) was found to induce the activation of the pathogenesis-related protein production of chitinase enzyme as well as beta 1,3-glucanase for effective immunity and resistance of tomato plant to the invasive pathogen Alternaria solani (Raut and Borkar, 2014 ). Also, hydrogen peroxide, abscisic acid, and 2,4 dichlorophenoxy acetic acid chemical inducers applied exogenously to potato plant challenged with A. solani was able to resist the pathogen infection as a result of increase in plant intracellular concentration of peroxidase, phenylalanine ammonia lyase, and polyphenoloxidase enzymes.…”