Treatment with the herbicide granstar induces oxidative stress in cereal leaves

Disks excised from leaves and intact 7-day-old plants of winter wheat (Triticum aestivum L., cv. Mironovskaya 808), winter rye (Secale cereale L., cv. Estafeta Tatarstana), maize (Zea mays L., hybrid Kollektivnyi 172 MV), and common wild oat (Avena fatua L.) were treated with the xenobiotic (herbicide Granstar, 3–300 μg/l), and the effects of short-term action (up to 3 h) and long-term aftereffect (up to 3 days) on physiological and biochemical indices related to oxidative stress development were studied. Changes (predominantly toward increase) of lipid peroxidation intensity, superoxide anion-radical (O 2 ·− )generation, total antioxidant activity, and antioxidant enzymes (superoxide dismutase, catalase, and ascorbate peroxidase) under the action of the herbicide were observed. Plant responses depended nonlinearly on the herbicide concentration and duration of treatment. Winter wheat and winter rye turned out to be more tolerant, and maize and common wild oat were less tolerant. It is concluded that oxidative stress is the basis for cereal plant responses to the herbicide action.