Oxygen activation at the plasma membrane: relation between superoxide and hydroxyl radical production by isolated membranes
Oxygen activation at the plasma membrane: relation between superoxide and hydroxyl radical production by isolated membranes
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DOI：
10.1007/s00425-011-1379-y
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发表时间：
2011-07-01
期刊：
影响因子：
4.3
通讯作者：
Krieger-Liszkay, Anja
中科院分区：
文献类型：
--
作者：
Heyno, Eiri;Mary, Veronique;Krieger-Liszkay, Anja
利用EPR自旋捕获技术和特异性染料研究了黄化大豆幼苗下胚轴和根的生长区和非生长区以及黄化玉米幼苗胚芽鞘和根的离体质膜中活性氧（羟自由基、超氧自由基和过氧化氢）的产生。NAD（P）H介导的超氧化物的产生在所有质膜样品。羟基自由基只产生的膜下胚轴生长区时，芬顿催化剂（FeEDTA）的存在。相比之下，在膜从其他部分的幼苗自发羟基自由基的形成率低，观察到由于存在少量的紧密结合的过氧化物酶。可以得出结论，质外体羟基自由基的产生完全依赖于，或在很大程度上，在细胞壁中定位的过氧化物酶。在大豆质膜从生长区的下胚轴药理学试验表明，超氧化物的产生可能是由于至少两种酶的作用，NADPH氧化酶和甲萘醌的存在下，醌还原酶。
Production of reactive oxygen species (hydroxyl radicals, superoxide radicals and hydrogen peroxide) was studied using EPR spin-trapping techniques and specific dyes in isolated plasma membranes from the growing and the non-growing zones of hypocotyls and roots of etiolated soybean seedlings as well as coleoptiles and roots of etiolated maize seedlings. NAD(P)H mediated the production of superoxide in all plasma membrane samples. Hydroxyl radicals were only produced by the membranes of the hypocotyl growing zone when a Fenton catalyst (FeEDTA) was present. By contrast, in membranes from other parts of the seedlings a low rate of spontaneous hydroxyl radical formation was observed due to the presence of small amounts of tightly bound peroxidase. It is concluded that apoplastic hydroxyl radical generation depends fully, or for the most part, on peroxidase localized in the cell wall. In soybean plasma membranes from the growing zone of the hypocotyl pharmacological tests showed that the superoxide production could potentially be attributed to the action of at least two enzymes, an NADPH oxidase and, in the presence of menadione, a quinone reductase.