scholarly journals A role for the RabA4b effector protein PI-4Kβ1 in polarized expansion of root hair cells in Arabidopsis thaliana

2006 ◽  
Vol 172 (7) ◽  
pp. 991-998 ◽  
Author(s):  
Mary L. Preuss ◽  
Aaron J. Schmitz ◽  
Julie M. Thole ◽  
Heather K.S. Bonner ◽  
Marisa S. Otegui ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Hair Cells ◽  
Root Hair ◽  
Root Hairs ◽  
Developmentally Regulated ◽  
Domain Specific ◽  
Polarized Secretion ◽  
Phosphatidylinositol 4 ◽  
Golgi Network ◽  
Root Hair Cells

The RabA4b GTPase labels a novel, trans-Golgi network compartment displaying a developmentally regulated polar distribution in growing Arabidopsis thaliana root hair cells. GTP bound RabA4b selectively recruits the plant phosphatidylinositol 4-OH kinase, PI-4Kβ1, but not members of other PI-4K families. PI-4Kβ1 colocalizes with RabA4b on tip-localized membranes in growing root hairs, and mutant plants in which both the PI-4Kβ1 and -4Kβ2 genes are disrupted display aberrant root hair morphologies. PI-4Kβ1 interacts with RabA4b through a novel homology domain, specific to eukaryotic type IIIβ PI-4Ks, and PI-4Kβ1 also interacts with a Ca2+ sensor, AtCBL1, through its NH2 terminus. We propose that RabA4b recruitment of PI-4Kβ1 results in Ca2+-dependent generation of PI-4P on this compartment, providing a link between Ca2+ and PI-4,5P2–dependent signals during the polarized secretion of cell wall components in tip-growing root hair cells.

The homeobox gene GLABRA2 is required for position-dependent cell differentiation in the root epidermis of Arabidopsis thaliana

Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1253-1260 ◽  
Author(s):  
J.D. Masucci ◽  
W.G. Rerie ◽  
D.R. Foreman ◽  
M. Zhang ◽  
M.E. Galway ◽  
...  
Keyword(s):  
Epidermal Cell ◽  
Hair Cells ◽  
Root Hair ◽  
Root Hairs ◽  
Homeobox Gene ◽  
Epidermal Cells ◽  
Wild Type ◽  
Cell Identity ◽  
Root Epidermis ◽  
Root Hair Cells

The role of the Arabidopsis homeobox gene, GLABRA 2 (GL2), in the development of the root epidermis has been investigated. The wild-type epidermis is composed of two cell types, root-hair cells and hairless cells, which are located at distinct positions within the root, implying that positional cues control cell-type differentiation. During the development of the root epidermis, the differentiating root-hair cells (trichoblasts) and the differentiating hairless cells (atrichoblasts) can be distinguished by their cytoplasmic density, vacuole formation, and extent of elongation. We have determined that mutations in the GL2 gene specifically alter the differentiation of the hairless epidermal cells, causing them to produce root hairs, which indicates that GL2 affects epidermal cell identity. Detailed analyses of these differentiating cells showed that, despite forming root hairs, they are similar to atrichoblasts of the wild type in their cytoplasmic characteristics, timing of vacuolation, and extent of cell elongation. The results of in situ nucleic acid hybridization and GUS reporter gene fusion studies show that the GL2 gene is preferentially expressed in the differentiating hairless cells of the wild type, during a period in which epidermal cell identity is believed to be established. These results indicate that the GL2 homeodomain protein normally regulates a subset of the processes that occur during the differentiation of hairless epidermal cells of the Arabidopsis root. Specifically, GL2 appears to act in a cell-position-dependent manner to suppress hair formation in differentiating hairless cells.

scholarly journals Calcium influx at the tip of growing root-hair cells of Arabidopsis thaliana

Planta ◽  
1992 ◽  
Vol 187 (4) ◽  
Author(s):  
JohnW. Schiefelbein ◽  
Al Shipley ◽  
Paul Rowse
Keyword(s):  
Arabidopsis Thaliana ◽  
Hair Cells ◽  
Root Hair ◽  
Calcium Influx ◽  
Root Hair Cells

Root Hair Specific Proteins in Glycine max

1987 ◽  
Vol 42 (5) ◽  
pp. 537-541 ◽  
Author(s):  
Dietrich Werner ◽  
Andreas Bernd Wolff
Keyword(s):  
Glycine Max ◽  
Root System ◽  
Hair Cells ◽  
Root Hair ◽  
Root Hairs ◽  
Target Cells ◽  
Molecular Weights ◽  
Organ Specific ◽  
Specific Proteins ◽  
Root Hair Cells

Abstract In root hairs from seedlings of Glycine max cultivars, isolated from the root system and com­ pared with the complete organ, specific soluble proteins have been found. By FPLC chromatography and SDS gel electrophoresis root hair specific proteins with molecular weights of 13, 21, 34, 38 and 42 kDa were separated. Additionally, proteins with molecular weights of 12, 20, 69 and 74 kDa were significantly enriched in root hairs compared to roots without root hairs. By using CNBr activated Sepharose with antibodies against the root system without root hairs, the pres­ ence of root hair specific proteins was confirmed in extracts from isolated root hair cells. Enrichment of Fe and Ca in some of the proteins from the root hairs is demonstrated. The present knowledge of the biochemical specificity of legume root hairs, the target cells of Rhizobium and Bradyrhizobium infection, is discussed.

Local Positive Feedback Regulation Determines Cell Shape in Root Hair Cells

Science ◽  
2008 ◽  
Vol 319 (5867) ◽  
pp. 1241-1244 ◽  
Author(s):  
S. Takeda ◽  
C. Gapper ◽  
H. Kaya ◽  
E. Bell ◽  
K. Kuchitsu ◽  
...  
Keyword(s):  
Hair Cells ◽  
Positive Feedback ◽  
Root Hair ◽  
Cell Shape ◽  
Feedback Regulation ◽  
Root Hair Cells

The role of plant villin in the organization of the actin cytoskeleton, cytoplasmic streaming and the architecture of the transvacuolar strand in root hair cells of Hydrocharis

Planta ◽  
2000 ◽  
Vol 210 (5) ◽  
pp. 836-843 ◽  
Author(s):  
Motoki Tominaga ◽  
Etsuo Yokota ◽  
Luis Vidali ◽  
Seiji Sonobe ◽  
Peter K. Hepler ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Hair Cells ◽  
Root Hair ◽  
Cytoplasmic Streaming ◽  
Root Hair Cells

Colonization and invasion of peanut (Arachis hypogaea L.) roots by gusA-marked Bradyrhizobium sp.

2001 ◽  
Vol 79 (6) ◽  
pp. 733-738 ◽  
Author(s):  
Eiji Uheda ◽  
Hiroyuki Daimon ◽  
Fumiki Yoshizako
Keyword(s):  
Cell Wall ◽  
Arachis Hypogaea ◽  
Hair Cells ◽  
Root Hair ◽  
Root Nodules ◽  
Lateral Roots ◽  
Middle Lamella ◽  
Root Surface ◽  
Arachis Hypogaea L ◽  
Root Hair Cells

Tufted rosettes of long root hairs occur in axils of young lateral roots of peanut (Arachis hypogaea L.). Analyses of serial sections of the axils of emerging lateral roots revealed multiple layers of root hair cells. The cells of the outer layer partially overlie the adjacent cells of the inner layer. When Bradyrhizobium cells with an integrated gusA gene were inoculated onto peanut roots and the roots subsequently stained with X-gluc, blue spots indicating the presence of colonies of Bradyrhizobium were observed in the axils of lateral roots. Blue spots were also observed in other areas on the root surface. Transmission electron microscopy revealed that the primary wall of the base of root hair cells has a loose construction. Upon inoculation of Bradyrhizobium, bacteria entered only between root hair cells through the middle lamella. In other areas of the root surface other than axils of lateral roots, the cells had modified walls similar to those at the base of root hair cells. However, invasion by Bradyrhizobium of the cell wall was not observed.Key words: Arachis hypogaea, gusA-marked Bradyrhizobium, cell wall, invasion, root hair cell, root nodules.

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