Anoxia tolerance in rice roots acclimated by several different periods of hypoxia.
Rice (Oryza sativa L.) seedlings were subjected to hypoxic pretreatment (H-PT; incubated in 5% O2 atmosphere) for various lengths of time followed by an anoxic stress. Anoxia tolerance of rice roots was improved with increasing duration of H-PT, but longer H-PT than 12 h gave no additional improvement. Concentrations of ATP and ethanol, and activities of pyruvate decarboxylase (EC 4.1.1.1) and alcohol dehydrogenase (EC 1.1.1.1) in the roots were increased by H-PT, and the times and patterns of increasing in these concentrations and activities were similar to those of increasing in the anoxia tolerance. These results suggest that the H-PT may increase anoxia tolerance due to maintenance of ATP levels with rapid induction of ethanolic fermentation, and hypoxic acclimation may occur within 12 h.
Kato-Noguchi
Hisashi
H
Department of Biochemistry and Food Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa 761-0795, Japan. hisashi@ag.kagawa-u.ac.jp
D000222:Adaptation, Physiological; D000255:Adenosine Triphosphate / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D006019:Glycolysis; D012275:Oryza / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D018517:Plant Roots / Q000378:metabolism*; D036226:Seedlings; D013997:Time Factors
D000431:Ethanol; D000255:Adenosine Triphosphate; D010100:Oxygen