Trichoderma mediated induced systemic resistance in cucurbits against cucumber mosaic virus (cmv)

Trichoderma mediated systemic resistance is often associated with the onset of defense mechanisms by expression of various defense related enzymes such as β-1-3-glucanase, chitins, phenylalanine ammonia lyase (PAL), peroxidase (PO), polyphenol oxidase (PPO) and phenols. The present investigation was undertaken to demonstrate and to exploit the T.harzianum isolated from the rhizosphere soil of healthy pumpkin plants for induction of systemic resistance against Cucumber mosaic virus (CMV), the causative agent of cucumber mosaic virus disease in cucurbits. Trichoderma treated pumpkin plants challenged with CMV not only showed a pronounced and significant reduction in percent disease incidence (PDI) but also a significant reduction in virus concentration (ELISA) and exhibited maximum activity of PO, PPO and increase in the concentration of proteins, phenols as compared to the plants challenged with CMV alone at 25 days after inoculation (DAI). Trichoderma -treated plants were more developed than non treated plants throughout the experiment. Percentage of seed germination, symptom rating (%), plant height and yield measurements were also enhanced in the Trichoderm -treated plants inoculated with the virus. Expression of an additional 21.5 kDa protein in PAGE analysis indicates the induction of xylanase has shown to induce ethylene production and plant defense response in pre-treated plants.