Department of Plant Sciences, Texas A&M University, College Station, Texas 77843.
Plant Physiol. 1970 May;45(5):553-7. doi: 10.1104/pp.45.5.553.
Coumarin, at concentrations between 1.0 and 0.1 mm, inhibited red light-induced opening of the etiolated bean hypocotyl hook. In addition, anthocyanin synthesis and geotropic bending were inhibited. Coumarin stimulated ethylene synthesis, and ethylene was shown to mediate the inhibitory actions of coumarin. This conclusion was supported by: (a) the parallel concentration dependence and time sequence of hook closing and ethylene synthesis, (b) the restriction of the bulk of coumarin-induced ethylene production to the curved portion of the hook where opening is expressed, (c) the ability of both coumarin and ethylene to reclose partially opened hooks, and (d) the ability of exogenous ethylene, in the amounts produced by coumarintreated hooks, to duplicate the inhibitory effects of coumarin. There was an increasing stimulation of growth of the straight portion of the hypocotyl hook section as coumarin concentrations were increased from 0.1 to 1.0 mm. This action of coumarin was not duplicated by ethylene and occurred regardless of the presence or absence of added ethylene. The results of this study suggest that many actions of coumarin in growth systems are mediated by ethylene produced in response to the coumarin.
香豆素在 1.0 到 0.1 毫米浓度之间，抑制了红光诱导的黄化菜豆下胚轴弯钩的打开。此外，还抑制了花青素的合成和向地性弯曲。香豆素刺激乙烯的合成，并且证明乙烯介导了香豆素的抑制作用。这一结论得到了以下支持：(a) 弯钩关闭和乙烯合成的平行浓度依赖性和时间序列，(b) 香豆素诱导的乙烯产生的大部分局限于弯钩的弯曲部分，在那里表达了打开，(c) 香豆素和乙烯都能够重新关闭部分打开的弯钩，以及 (d) 外源乙烯在香豆素处理的弯钩中产生的量，能够复制香豆素的抑制作用。随着香豆素浓度从 0.1 增加到 1.0 毫米，下胚轴弯钩部分的直段生长受到越来越大的刺激。这种香豆素的作用不能被乙烯复制，并且无论是否添加了乙烯，都会发生。本研究的结果表明，香豆素在生长系统中的许多作用是通过响应香豆素产生的乙烯来介导的。
