a class of substances that in minute amounts regulate or modify the growth of plants, especially root formation, bud growth, and fruit and leaf drop.
Origin of auxin
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any of various plant hormones, such as indoleacetic acid, that promote growth and control fruit and flower development. Synthetic auxins are widely used in agriculture and horticulture
Word Origin for auxin
C20: from Greek auxein to grow
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Online Etymology Dictionary, © 2010 Douglas Harper
Any of various hormones or similar substances that promote and regulate the growth and development of plants. Auxins are produced in the meristem of shoot tips and move down the plant, causing various effects. Auxins cause the cells below the shoot apex to expand or elongate, and this (rather than cell division) is what causes the plant to increase in height. In woody plants, auxins also stimulate cell division in the cambium, which produces vascular tissue. Auxins inhibit the growth of lateral buds so that the plant grows upwards more than outwards. They can be produced artificially in laboratories for such purposes as speeding plant growth and regulating how fast fruit will ripen.
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