Centro de Biotecnología y Genómica de Plantas (U.P.M. - I.N.I.A.), Campus de Montegancedo, Pozuelo de Alarcón (Madrid), Spain.
Plant Signal Behav. 2010 Dec;5(12):1642-4. doi: 10.4161/psb.5.12.13810. Epub 2010 Dec 1.
The regulation of cellular auxin levels is a critical factor in determining plant growth and architecture, as indole-3-acetic acid (IAA) gradients along the plant axis and local IAA maxima are known to initiate numerous plant growth responses. The regulation of auxin homeostasis is mediated in part by transport, conjugation and deconjugation, as well as by de novo biosynthesis. However, the pathways of IAA biosynthesis are yet not entirely characterized at the molecular and biochemical level. It is suggested that several biosynthetic routes for the formation of IAA have evolved. One such pathway proceeds via the intermediate indole-3-acetamide (IAM), which is converted into IAA by the activity of specific IAM hydrolases, such as Arabidopsis AMIDASE1 (AMI1). In this article we present evidence to support the argument that AMI1-dependent IAA synthesis is likely not to be used during the first two days of seedling development.
细胞内生长素水平的调节是决定植物生长和形态建成的关键因素，因为已知植物轴上的吲哚-3-乙酸 (IAA) 梯度和局部 IAA 最大值会引发许多植物生长反应。生长素的动态平衡主要通过运输、共轭和去共轭以及从头生物合成来调节。然而，在分子和生化水平上，IAA 生物合成的途径尚未完全阐明。有人提出，已经形成了几种 IAA 形成的生物合成途径。其中一条途径是通过中间产物吲哚-3-乙酰胺 (IAM) 进行的，IAM 可以通过特定的 IAM 水解酶（如拟南芥酰胺酶 1（AMI1））的活性转化为 IAA。在本文中，我们提供了证据支持这样一个观点，即 AMI1 依赖性 IAA 合成在幼苗发育的头两天可能不会被利用。
