Plasma membrane NADH oxidase of maize roots responds to gravity and imposed centrifugal forces

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• 作者：Bacon ; Emily ; James Morré ; D.
• 关键词：auxin ; gravity ; NADH oxidase periodic ; plasma membrane ; Zea mays ; 2 ; 4-D ; 2 ; 4-dicholorophenoxyacetic acid ; A ; absorbance ; g ; gravity ; NOX protein ; external plasma membrane-associated NADH oxidase ; RSD ; right side (root tip) down ; USD ; upside down (root tip
• 刊名：Plant Physiology and Biochemistry
• 出版年：2001
• 出版时间：June, 2001
• 年：2001
• 卷：39
• 期：6
• 页码：487-494
• 全文大小：130 K

文摘

NADH oxidase activities measured with excised roots of dark-grown maize (Zea mays) seedlings and with isolated plasma membrane vesicles from roots of dark-grown maize oscillated with a regular period length of 24 min and were inhibited by the synthetic auxin 2,4-dichorophenoxyacetic acid. The activities also responded to orientation with respect to gravity and to imposed centrifugal forces. Turning the roots upside down resulted in stimulation of the activity with a lag of about 10 min. Returning the sections to the normal upright position resulted in a return to initial rates. The activity was stimulated reversibly to a maximum of about 2-fold with isolated plasma membrane vesicles, when subjected to centrifugal forces of 25 to 250 × g for 1 to 4 min duration. These findings are the first report of a gravity-responsive enzymatic activity of plant roots inhibited by auxin and potentially related to the gravity-induced growth response.