Evaluation of antioxidant gene expression in tomato plants inoculated by Cucumber mosaic virus after treatment with salicylic and jasmonic acids

Cucumber mosaic virus (CMV) is one of the most important viruses which causes yield reduction in tomato. In this experiment, the role of salicylic and jasmonic acids was investigated in the gene expression of antioxidant enzymes and induction of resistance to oxidative stress due to CMV inoculation in tomato (Falat cultivar). Results showed that in control plants expression of genes encoding catalase (CAT) and peroxidase (POX) enzymes gradually decreased to 15 days post inoculation (dpi), but expression of superoxide dismutase encoding gene (SOD) was increased at 15 dpi. In CMV inoculated plants, CAT gene was down-regulated, but POX gene was up-regulated to 8 dpi. SOD gene expression also increased in CMV inoculated plants to 15 dpi. The highest expression rate of POX observed at 15 dpi in SA treated plants which was 120% greater than before hormone application. Hormone application decreased the disease severity and symptoms to 80%. In Falat cultivar, peroxidase role in scavenging of H2O2 was greater than catalase and in order to inducing resistance, we can use SA and JA just before virus infection.