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+JA treatment and the highest activity of superoxide dismutase (SOD) and phenylalanine ammonia lyase (PAL) was related to SA+JA+CMV 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. تفاصيل المقالة

In order to assess the effects of zinc oxide nanoparticles (ZO-NP) on soybean seed germination under drought stress induced by polyethylene glycol, a factorial experiment was conducted in a completely randomized design at the University of Mohaghegh Ardabili, Ardabil, Iran, in 2013. The experiment consisted of three levels of drought (0, -0.5 and -1 MPa) and various concentrations of ZO-NP (0, 0.5 and 1 g lit-1). The soybean seeds used in this experiment was the DPX prepared from the Moghan Agricultural Research Center. The results showed that drought stress reduced the activity of peroxidase, superoxide dismutase, malate synthase and isocitrate lyase enzymes together with the germination rate, ascorbate and alpha-tocopherol concentration. However, the use of ZO-NP could counteract the adverse effects of drought, so that non-enzymatic antioxidant levels and antioxidant enzyme activity was increased and this improved the germination rate. Applying ZO-NP increased the activity of isocitrate lyase and malate synthase enzymes. Based on these results, it seems that the use of ZN-OP can be one way to mitigate the adverse effects of drought stress during soybean germination. تفاصيل المقالة