Premium
The control of root hair formation: suggested mechanisms
Author(s) -
Michael Gerhard
Publication year - 2001
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/1522-2624(200104)164:2<111::aid-jpln111>3.0.co;2-a
Subject(s) - root hair , rhizosphere , mechanism (biology) , chemistry , root (linguistics) , limiting , biophysics , biology , biochemistry , physics , philosophy , genetics , gene , mechanical engineering , linguistics , quantum mechanics , bacteria , engineering
Little is known about the physiological regulation of root hair development. Though the literature on the topic is fragmentary, with many gaps, it has been used to put forward some proposals for a central regulatory mechanism, taking note especially of the strong physiological influence of environmental factors on root hair formation. A hypothesis which implicates ethylene (ET) in this mechanism is proposed. This hypothesis is supported by numerous indications and observations in the literature about the effect of ET on cell wall formation and cell wall properties during the phase of root expansion and hair formation. It is assumed that environmental conditions control the effective ET concentration in epidermal hair‐forming cells; they influence root development and ET production, while, through affecting the rhizosphere, they modify gas exchange at the root surface, accelerating removal of ET thereby limiting its function in hair formation. In such a way the effects of various specific factors (e.g. soil temperature, bulk density, gas exchange at the root surface or the effect of nutrients) might be manifestations of a central regulatory mechanism. The hope is that this hypothesis will stimulate further research and some suggestions are made as to the direction such research might take.