The effect of salicylic acid and jasmonic acid on the symptoms of the disease and the expression of defense genes on a greenhouse cucumber infected with CMV

Cucumber is one of the most important vegetable and summer crops economically and is the fourth most cultivated plant in the world after tomatoes and potatoes. In this study, the effect of plant inducers including salicylic acid and jasmonic acid on the viral disease of greenhouse cucumber with Cucumber mosaic virus (CMV) and also the expression of defense genes was investigated. Treatments included plants treated with pathogenic virus alone, salicylic acid with virus, jasmonic acid and virus, and salicylic acid and jasmonic with virus. The results of this study showed that the maximum severity of the disease caused by CMV virus was observed in the plant treated with CMV virus only 68.85%. In the treatment of salicylic acid and jasmonic acid with CMV virus, the severity of symptoms was significantly reduced and so that the severity of the disease in hormonal treatments (salicylic acid + jasmonic acid) with the virus reached 10.23%. In the second part of this study, the effect of these treatments on the expression of four genes peroxidase, catalase, superoxide dismutase and phenylalanine ammonialysis was done. The results showed that the expression of genes related to peroxidase (POX), catalase (CAT), superoxide dismutase and phenylalanine dismutase enzymes in treated plants had an upward trend until the ninth day after treatment. However, this upward trend was much less observed in control plants (treated with virus water). The highest level of gene expression in the studied enzymes compared to the control plant (inoculated using distillate) was related to the enzyme catalase (401.7), followed by peroxidase enzymes (266.8), respectively. ), Superoxide dismutase (152.7) and phenylalanine ammonialyase (101.8). According to the results of this study, salicylic acid and jasmonic acid, by inducing more plant defense mechanisms such as defense enzymes, increase plant resistance to CMV virus and thus reduce the symptoms of this virus in cucumber plant.