Influence of salicylic and jasmonic acids on the antioxidant systems of tomato (Solanum lycopersicum cv. Superchief) plants under biotic stresses

Changes in the activity of antioxidant enzymes, proline, and total soluble carbohydrates (TSC) were evaluated in tomato (Solanum lycopercicum cv. Superchief) plants in response to salicylic acid (SA) and jasmonic acid (JA) and inoculation with CMV (Cucumber mosaic virus) on days 0, 1, 2, 4, 6, 8, and 15 after virus inoculation (dpi). Results showed that proline content increased in all treatments except for control while TSC content decreased in all treatments except the control. TSC content decreased by 50% in CMV treated plants, but the reduction was very slow in hormone treatments. SA decreased the catalase (CAT) activity until 6 dpi and then increased CAT activity to 15 dpi while other treatments except the control increased CAT activity over time. The highest activity of peroxidase (POD) was observed in SA treatment and the highest activity of superoxide dismutase (SOD) and phenylalanine ammonia lyase (PAL) was related to SA␏舱 treatment. These results show that combination of SA with JA can control the CMV in tomato plants cv. Superchief through the inhibition of TSC reduction which is an indicator of normal photosynthesis capacity.