Back to Search
Start Over
ROOT HAIR DEFECTIVE4 Encodes a Phosphatidylinositol-4-Phosphate Phosphatase Required for Proper Root Hair Development in Arabidopsis thaliana.
- Source :
-
Plant Cell . Feb2008, Vol. 20 Issue 2, p381-395. 15p. 7 Diagrams, 1 Chart, 3 Graphs. - Publication Year :
- 2008
-
Abstract
- Polarized expansion of root hair cells in Arabidopsis thaliana is improperly controlled in root hair-defective rhd4-1 mutant plants, resulting in root hairs that are shorter and randomly form bulges along their length. Using time-lapse fluorescence microscopy in rhd4-1 root hairs, we analyzed membrane dynamics after labeling with RabA4b, a marker for polarized membrane trafficking in root hairs. This revealed stochastic loss and recovery of the RabA4b compartment in the tips of growing root hairs, consistent with a role for the RHD4 protein in regulation of polarized membrane trafficking in these cells. The wild-type RHD4 gene was identified by map-based cloning and was found to encode a Sac1p-like phosphoinositide phosphatase. RHD4 displayed a preference for phosphatidylinositol-4-phosphate [PI(4)P] in vitro, and rhd4-1 roots accumulated higher levels of PI(4)P in vivo. In wild-type root hairs, PI(4)P accumulated primarily in a tip-localized plasma membrane domain, but in rhd4-1 mutants, significant levels of PI(4)P were detected associated with internal membranes. A fluorescent RHD4 fusion protein localized to membranes at the tips of growing root hairs. We propose that RHD4 is selectively recruited to RabA4b-labeled membranes that are involved in polarized expansion of root hair cells and that, in conjunction with the phosphoinositide kinase PI-4Kβ1, RHD4 regulates the accumulation of PI(4)P on membrane compartments at the tips of growing root hairs. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10404651
- Volume :
- 20
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Plant Cell
- Publication Type :
- Academic Journal
- Accession number :
- 31749083
- Full Text :
- https://doi.org/10.1105/tpc.107.054304