Document Type: Research Paper
PhD students of Crop Physiology, Faculty of Agriculture, Ilam University, Ilam, Iran.
Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
Faculty of Agriculture, University of Ilam, Ilam, Iran
Compounds which are able to reduce the damaging effects of various stresses such as drought could be of great importance. In this research, arginine was used as a precursor of nitric oxide or polyamines and the effect of this compound on alleviation of oxidative damages under drought stress has been investigated. Experimental treatments included arginine at three levels (0, 10 and 20 µmol) and drought stress (induced by polyethylene glycol6000) at the levels of 0, 13.5% and 17% (W/V).This experiment was conducted as a completely randomized design in a factorial arrangement with three replications. The application of arginine through the root medium increased drought tolerance of ajwain (Trachyspermum ammi) seedlings. Arginine profoundly induced the activities of phenylalanine ammonia-lyase and polyphenol oxidase in plants which led to reduction in electrolyte leakage and increasing in relative water content, photosynthetic pigments (chlorophyll a, b, total chlorophyll and carotenoids), polyphenol compounds, flavonoids, anthocyanin content and soluble sugar content. It is concluded that the application of arginine appear to induce pre-adaptive responses to drought stress leading to promote protective reactions.