تاثیر اسید سالیسیلیک و جاسمونیک بر بیان ژن‌های آنتی‌اکسیدانت در گوجه‌فرنگی(Solanum lycopersicum cv. Superchief) مایه‌زنی شده با ویروس موزاییک خیار (CMV)

In this experiment, the effect of salicylic acid (SA) and jasmonic acid (JA) was investigated on the expression of genes encoding antioxidant enzymes and induction of resistance to oxidative stress due to Cucumber mosaic virus (CMV) infection in tomato (Superchief cultivar) plants. Treatments were included of CMV, SA (1 mM), JA (0.5 mM), SA+JA, SA+CMV, JA+CMV, SA+JA+CMV and a control. Samples were taken at 0, 1, 2, 4, 6, 8, and 15 days post inoculation (dpi). Results showed that changes in the expression level of genes encoding peroxidase (POD) and superoxide dismutase (SOD) enzymes were similar extensively in control plants and increased at 15 dpi, but the expression level of genes encoding catalase (CAT) enzyme were gradually decreased until 15 dpi. In CMV infected plants, CAT gene was down-regulated, but POD and SOD genes were up-regulated to 6 to 15 dpi, respctively. The highest expression rate of POD and SOD genes was observed at 15 dpi in SA+JA+CMV treatment which was 165 and 120% greater than before hormone application, respectively. Expression of CAT gene was greater in JA included treatments that is an indicator of reductive effect of SA on transcription and activity of catalase at the early stages of infection to utilize the signal of H2O2 radical as a secondary messenger in establishment and transduction of signal. In conclusion, peroxidase role in scavenging of H2O2 was greater than catalase in Superchief cultivar, and it is possible to use the combination of two hormones for inhibiting the oxidative stress before virus infection.