We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Identification and characterization of Arabidopsis indole-3-butyric acid response mutants defective in novel peroxisomal enzymes.
- Authors
Zolman, Bethany K; Martinez, Naxhiely; Millius, Arthur; Adham, A Raquel; Bartel, Bonnie
- Abstract
Genetic evidence suggests that indole-3-butyric acid (IBA) is converted to the active auxin indole-3-acetic acid (IAA) by removal of two side-chain methylene units in a process similar to fatty acid beta-oxidation. Previous studies implicate peroxisomes as the site of IBA metabolism, although the enzymes that act in this process are still being identified. Here, we describe two IBA-response mutants, ibr1 and ibr10. Like the previously described ibr3 mutant, which disrupts a putative peroxisomal acyl-CoA oxidase/dehydrogenase, ibr1 and ibr10 display normal IAA responses and defective IBA responses. These defects include reduced root elongation inhibition, decreased lateral root initiation, and reduced IBA-responsive gene expression. However, peroxisomal energy-generating pathways necessary during early seedling development are unaffected in the mutants. Positional cloning of the genes responsible for the mutant defects reveals that IBR1 encodes a member of the short-chain dehydrogenase/reductase family and that IBR10 resembles enoyl-CoA hydratases/isomerases. Both enzymes contain C-terminal peroxisomal-targeting signals, consistent with IBA metabolism occurring in peroxisomes. We present a model in which IBR3, IBR10, and IBR1 may act sequentially in peroxisomal IBA beta-oxidation to IAA.
- Publication
Genetics, 2008, Vol 180, Issue 1, p237
- ISSN
0016-6731
- Publication type
Journal Article
- DOI
10.1534/genetics.108.090399