Oxidative Status and Antioxidative Response to Attack and Different Nitrogen Levels in Winter Wheat Varieties.

Abiotic and biotic stresses, such as mineral nutrition deficiency (especially nitrogen) and attack, pose a global threat with devastating impact on wheat yield and quality losses worldwide. This preliminary study aimed to determine the effect of inoculation and two different nitrogen levels on oxidative status and antioxidative response in nine wheat varieties. Level of lipid peroxidation, activities of antioxidant enzymes (catalase, ascorbate peroxidase, glutathione reductase), phenolics, and chloroplast pigments content were measured. In general, wheat variety, nitrogen, and treatment had an impact on all tested parameters. The most significant effect had a low nitrogen level itself, which mostly decreased activities of all antioxidant enzymes and reduced the chloroplast pigment content. At low nitrogen level, treatment increased activities of some antioxidative enzymes, while in a condition of high nitrogen levels, antioxidative enzyme activities were mostly decreased due to treatment. The obtained results provided a better understanding on wheat defense mechanisms against under different nitrogen treatments and can serve as an additional tool in assessing wheat tolerance to various environmental stress conditions.