MSU-DOE Plant Research Laboratory, Michigan State University, 48824, East Lansing, MI, USA.
Planta. 1979 Jan;146(3):293-301. doi: 10.1007/BF00387801.
Homogenates of etiolated pea (Pisum sativum L.) shoots formed ethylene upon incubation with 1-aminocyclopropane-1-carboxylic acid (ACC). In-vitro ethylene formation was not dependent upon prior treatment of the tissue with indole-3-acetic acid. When homogenates were passed through a Sephadex column, the excluded, high-molecular-weight fraction lost much of its ethylene-synthesizing capacity. This activity was largely restored when a heat-stable, low-molecular-weight factor, which was retarded on the Sephadex column, was added back to the high-molecular-weight fraction. The ethylene-synthesizing system appeared to be associated, at least in part, with the particulate fraction of the pea homogenate. Like ethylene synthesis in vivo, cell-free ethylene formation from ACC was oxygen dependent and inhibited by ethylenediamine tetraacetic acid, n-propyl gallate, cyanide, azide, CoCl3, and incubation at 40°C. It was also inhibited by catalase. In-vitro ethylene synthesis could only be saturated at very high ACC concentrations, if at all. Ethylene production in pea homogenates, and perhaps also in intact tissue, may be the result of the action of an enzyme that needs a heat-stable cofactor and has a very low affinity for its substrate, ACC, or it may be the result of a chemical reaction between ACC and the product of an enzyme reaction. Homogenates of etiolated pea shoots also formed ethylene with 2-keto-4-mercaptomethyl butyrate (KMB) as substrate. However, the mechanism by which KMB is converted to ethylene appears to be different from that by which ACC is converted.
将黄化豌豆（Pisum sativum L.）芽的匀浆与 1-氨基环丙烷-1-羧酸（ACC）一起孵育会形成乙烯。体外乙烯的形成不依赖于组织预先用吲哚-3-乙酸处理。当匀浆通过葡聚糖凝胶柱时，被排斥的高分子量部分失去了大部分合成乙烯的能力。当一种耐热的、低分子量的因子被添加回高分子量部分时，这种活性在很大程度上得到了恢复，而该因子在葡聚糖凝胶柱上被延迟。乙烯合成系统似乎至少部分与豌豆匀浆的颗粒部分有关。与体内乙烯合成一样，无细胞 ACC 形成乙烯也依赖于氧气，并被乙二胺四乙酸、正丙基没食子酸、氰化物、叠氮化物、CoCl3 和在 40°C 下孵育所抑制。它也被过氧化氢酶抑制。在体外，只有在非常高的 ACC 浓度下，乙烯的合成才能达到饱和，如果可以达到的话。豌豆匀浆中的乙烯产生，也许还有完整组织中的乙烯产生，可能是一种需要耐热辅助因子的酶的作用的结果，这种酶对其底物 ACC 的亲和力非常低，或者可能是 ACC 与酶反应产物之间的化学反应的结果。黄化豌豆芽的匀浆也可以用 2-酮-4-巯基甲基丁酸（KMB）作为底物形成乙烯。然而，KMB 转化为乙烯的机制似乎与 ACC 转化为乙烯的机制不同。
