Hormone interactions during lateral root formation.
Lateral root (LR) formation, the production of new roots from parent roots, is a hormone- and environmentally-regulated developmental process in higher plants. Physiological and genetic studies using Arabidopsis thaliana and other plant species have revealed the roles of several plant hormones in LR formation, particularly the role of auxin in LR initiation and primordium development, resulting in much progress toward understanding the mechanisms of auxin-mediated LR formation. However, hormone interactions during LR formation have been relatively underexamined. Recent studies have shown that the plant hormones, cytokinin and abscisic acid negatively regulate LR formation whereas brassinosteroids positively regulate LR formation. On the other hand, ethylene has positive and negative roles during LR formation. This review summarizes recent findings on hormone-regulated LR formation in higher plants, focusing on auxin as a trigger and on the other hormones in LR formation, and discusses the possible interactions among plant hormones in this developmental process.
Fukaki
Hidehiro
H
Department of Biology, Graduate School of Science, Kobe University, 1-1, Rokkodai, Kobe 657-8501, Japan. h-fukaki@port.kobe-u.ac.jp
Tasaka
Masao
M
D000040:Abscisic Acid / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D005030:Ethylenes / Q000378:metabolism; D005875:Gibberellins / Q000502:physiology; D007210:Indoleacetic Acids / Q000378:metabolism; D008954:Models, Biological; D010937:Plant Growth Regulators / Q000235:genetics / Q000502:physiology*; D018517:Plant Roots / Q000254:growth & development*; D015398:Signal Transduction
D005030:Ethylenes; D005875:Gibberellins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D000040:Abscisic Acid; C036216:ethylene