Physiological and oxidative stress responses of potato

Oxidative stress is a disturbance in the antioxidant balance leading to cellular damage. Reactive oxygen species (ROS) and especially hydrogen peroxide are the major contributor to the onset of oxidative stress in biological systems. Oxidation of cellular lipids, proteins, and DNA by ROS decreases cellular function and increases susceptibility to chronic diseases. Nonetheless, a relationship between reactive oxygen species metabolism and dormancy breaking in plant has been previously reported. Application of hydrogen peroxide or of catalase inhibitors (such thiourea) releases dormancy in these plants. In potato, little knowledge about the implication of reactive oxygen species metabolism in tuber dormancy release. Potato tuber is rich in polyphenols, ascorbic acid and carotenoids. Antioxidants such as polyphenols, ascorbic acid, and carotenoids have been shown to reduce DNA damage, inhibit cell proliferation, but improving immune cell function. Our purpose was to assess the effects of hydrogen peroxide and thiourea on dormancy breaking of potato tuber and on antioxydant composition.