Abstract
The exogenous application of natural plant resistance inducer is a new interesting way for disease management. From this point of view, this study investigated the effect of wheat grain priming with defensin on the resistance of the grown plants against the Fusarium wilt. The results showed that priming enhanced the antioxidant system represented in antioxidant enzymes (superoxide dismutase, polyphenol oxidase, soluble and cell wall-bound peroxidase) and non-enzymatic antioxidant compounds (proline, free soluble and cell wall-bound phenols) in the plants. This results in decreasing the H2O2 content and lipid peroxidation in these plants, which protects plants from the oxidative stress. Defensin priming not only improved the antioxidant system but also improved the hydrolysis processes. Under infection, the protease activity in the primed plants decreased compared to its highly significant increase in the non-primed group. Defensin priming also increased the activity of the phosphatases and amylase which increased the soluble phosphate and sugar. This served the high metabolic activity of the defensin-primed plants. The highly significant decrease in the shikimic acid content in the defensin-primed group ensured its high metabolic activity. All these changes are initiated by the regulation of defense signal molecules such as jasmonic and abscisic acids. This helped the plants grown from defensin-primed grains to overcome the Fusarium infection.