Activities of Catalase and Peroxidase in Wheat and Rice Plants under Conditions of Anoxia and Post-Anoxic Aeration

• Published in: Russian journal of plant physiology 2022-12, Vol.69 (6), Article 117
• Main Authors: Yemelyanov, V. V., Lastochkin, V. V., Prikaziuk, E. G., Chirkova, T. V.
• Format: Article
• Language: English
• Subjects: Actinomycin; Aeration; Anoxia; Antioxidants; Aquatic plants; Biomedical and Life Sciences; Brefeldin A; Catalase; Cell walls; Crop production; Cycloheximide; Cytosol; Detoxification; Electrophoresis; Enzymes; Gene expression; Guaiacol; Hydrogen peroxide; Hypoxia; Isoforms; Life Sciences; Oxidative stress; Oxygen; Peroxidase; Plant Physiology; Plant Sciences; Reaeration; Research Papers; Rice; Seedlings; Shoots; Stimulation; Wheat
• ISSN: 1021-4437; 1608-3407
• DOI: 10.1134/S1021443722060036

Effects of anoxia and subsequent reaeration on formation of hydrogen peroxide, and activities of catalase (EC 1.11.1.6) and guaiacol peroxidase (EC 1.11.1.7) were studied in wheat and rice plants that are contrasting in their tolerance to hypoxia. It was found that anoxia and reaeration, especially long-term, strongly increased the H 2 O 2 production in hypoxia-intolerant wheat plants. Meanwhile, such treatment did not significantly entail peroxide production in rice, which is tolerant to oxygen lack. In these tolerant plants, the activities of catalase, as well as intra- and extracellular guaiacol peroxidases, rapidly increased under anoxia and the following oxidative stress. By contrast, wheat did not display stimulation of catalase activity; activation of its peroxidase occurred only in the shoots after a short anoxia and long reaeration. The increased or stable activities of catalase and peroxidase in the rice seedlings, under anoxia and reaeration, were inhibited by cycloheximide and, to smaller extent, actinomycin D. In rice, the stimulation of catalase activity was accompanied by the increased expression of the corresponding genes, in particular, OsCatB and OsCatС . The activities of apoplastic peroxidases were suppressed by brefeldin A. Electrophoresis did not reveal the emergence of new isoforms of guaiacol peroxidase under anoxia and post-anoxic aeration. Meanwhile, the activities of the majority of preexisting isoforms in rice and individual isoforms in wheat were considerably stimulated under these conditions. It is suggested that, in the tolerant plants subjected to anoxia and post-anoxic aeration, the activation of apoplastic peroxidases fulfills an adaptive function decomposing hydrogen peroxide in the cell wall and preventing its penetration into the cytosol. Under long-term reaeration, detoxification of ROS in the rice cytosol may be favored by activation of catalase and intracellular peroxidase. Unlike rice, the absence of activation of the antioxidant enzymes in the wheat cell wall allows ROS to penetrate inside the cell where they are deactivated by cytoplasmic forms of guaiacol peroxidase. The efficient work of antioxidant enzymes under anoxia, followed by post-anoxic aeration, prevents ROS accumulation in the tolerant plant and, thus, represents an important adaptation to both lack of oxygen and subsequent oxidative stress.