Article
Peroxisomes as a Source of Auxin Signaling Molecules
Sub-cellular biochemistry
(2013)
Abstract
Peroxisomes house many metabolic processes that allow organisms to safely sequester reactions with potentially damaging byproducts. Peroxisomes also produce signaling molecules; in plants, these include the hormones indole-3-acetic acid (IAA) and jasmonic acid (JA). Indole-3-butyric acid (IBA) is a chain-elongated form of the active auxin IAA and is a key tool for horticulturists and plant breeders for inducing rooting in plant cultures and callus. IBA is both made from and converted to IAA, providing a mechanism to maintain optimal IAA levels. Based on genetic analysis and studies of IBA metabolism, IBA conversion to IAA occurs in peroxisomes, and the timing and activity of peroxisomal import and metabolism thereby contribute to the IAA pool in a plant. Four enzymes have been hypothesized to act specifically in peroxisomal IBA conversion to IAA. Loss of these enzymes results in decreased IAA levels, a reduction in auxin-induced gene expression, and strong disruptions in cell elongation resulting in developmental abnormalities. Additional activity by known fatty acid β-oxidation enzymes also may contribute to IBA β-oxidation via direct activity or indirect effects. This review will discuss the peroxisomal enzymes that have been implicated in auxin homeostasis and the importance of IBA-derived IAA in plant growth and development.
Keywords
- Indole-3-butyric acid,
- IBA,
- Indole-3-acetic acid,
- IAA,
- Auxin,
- Peroxisome
Disciplines
Publication Date
January 1, 2013
DOI
10.1007/978-94-007-6889-5_14
Citation Information
Gretchen M. Spiess and Bethany K. Zolman. "Peroxisomes as a Source of Auxin Signaling Molecules" Sub-cellular biochemistry Vol. 69 (2013) p. 257 - 281 Available at: http://works.bepress.com/bethany-zolman/3/