Peck S C, Kende H
MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing 48824-1312, USA.
Plant Mol Biol. 1995 May;28(2):293-301. doi: 10.1007/BF00020248.
Ethylene induced an increase in the accumulation of 1-aminocyclopropane-1-carboxylate (ACC) oxidase transcript level and enzyme activity in the first internode of 5- to 6-day-old etiolated pea (Pisum sativum L.) seedlings. Indole-3-acetic acid (IAA), which stimulates ethylene production by enhancing ACC synthase activity, also caused an increase in ACC oxidase transcript and activity levels. The IAA-induced increase in ACC oxidase mRNA level and enzyme activity was blocked by 2,5-norbornadiene (NBD), a competitive inhibitor of ethylene action. This indicates that IAA induced ACC oxidase through the action of ethylene. The level of ACC synthase mRNA and enzyme activity started to increase less than 1 h after the start of IAA treatment, whereas ACC oxidase activity and transcript levels began to rise after 2 h of IAA treatment. These results indicate that the enzymes of ethylene biosynthesis are sequentially induced after treatment of intact pea seedlings with IAA. The increase in ACC synthase activity leads to the production of ACC, which is converted by the low constitutive level of ACC oxidase activity to ethylene. Through a positive feedback loop, ethylene promotes the accumulation of ACC oxidase mRNA and the increase in ACC oxidase activity.
乙烯诱导5至6日龄黄化豌豆（Pisum sativum L.）幼苗第一节间中1-氨基环丙烷-1-羧酸（ACC）氧化酶转录水平和酶活性的积累增加。吲哚-3-乙酸（IAA）通过增强ACC合酶活性刺激乙烯产生，也导致ACC氧化酶转录和活性水平增加。IAA诱导的ACC氧化酶mRNA水平和酶活性增加被2,5-降冰片二烯（NBD）阻断，NBD是乙烯作用的竞争性抑制剂。这表明IAA通过乙烯的作用诱导ACC氧化酶。IAA处理开始后不到1小时，ACC合酶mRNA水平和酶活性开始增加，而ACC氧化酶活性和转录水平在IAA处理2小时后开始上升。这些结果表明，用IAA处理完整豌豆幼苗后，乙烯生物合成的酶被依次诱导。ACC合酶活性的增加导致ACC的产生，ACC由低组成水平的ACC氧化酶活性转化为乙烯。通过正反馈回路，乙烯促进ACC氧化酶mRNA的积累和ACC氧化酶活性的增加。
