scholarly journals Class III peroxidases PRX01, PRX44, and PRX73 potentially target extensins during root hair growth in Arabidopsis thaliana

2020 ◽  
Author(s):  
Eliana Marzol ◽  
Cecilia Borassi ◽  
Philippe Ranocha ◽  
Ariel. A. Aptekman ◽  
Mauro Bringas ◽  
...  
Keyword(s):  
Cell Wall ◽  
Hair Cells ◽  
Root Hair ◽  
Hair Growth ◽  
Water Soluble ◽  
Soil Conditions ◽  
Class Iii ◽  
Root Hair Growth ◽  
Class Iii Peroxidases ◽  
Root Hair Cells

AbstractRoot hair cells are important sensors of soil conditions. Expanding several hundred times their original size, root hairs grow towards and absorb water-soluble nutrients. This rapid growth is oscillatory and is mediated by continuous remodelling of the cell wall. Root hair cell walls contain polysaccharides and hydroxyproline-rich glycoproteins including extensins (EXTs).Class-III peroxidases (PRXs) are secreted into the apoplastic space and are thought to trigger either cell wall loosening, mediated by oxygen radical species, or polymerization of cell wall components, including the Tyr-mediated assembly of EXT networks (EXT-PRXs). The precise role of these EXT-PRXs is unknown.Using genetic, biochemical, and modeling approaches, we identified and characterized three root hair-specific putative EXT-PRXs, PRX01, PRX44, and PRX73. The triple mutant prx01,44,73 and the PRX44 and PRX73 overexpressors had opposite phenotypes with respect to root hair growth, peroxidase activity and ROS production with a clear impact on cell wall thickness.Modeling and docking calculations suggested that these three putative EXT-PRXs may interact with non-O-glycosylated sections of EXT peptides that reduce the Tyr-to-Tyr intra-chain distances in EXT aggregates and thereby may enhance Tyr crosslinking. These results suggest that these three putative EXT-PRXs control cell wall properties during the polar expansion of 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.

A role for CSLD3 during cell-wall synthesis in apical plasma membranes of tip-growing root-hair cells

2011 ◽  
Vol 13 (8) ◽  
pp. 973-980 ◽  
Author(s):  
Sungjin Park ◽  
Amy L. Szumlanski ◽  
Fangwei Gu ◽  
Feng Guo ◽  
Erik Nielsen
Keyword(s):  
Cell Wall ◽  
Hair Cells ◽  
Root Hair ◽  
Plasma Membranes ◽  
Cell Wall Synthesis ◽  
Root Hair Cells

O-Glycosylated Cell Wall Proteins Are Essential in Root Hair Growth

Science ◽  
2011 ◽  
Vol 332 (6036) ◽  
pp. 1401-1403 ◽  
Author(s):  
S. M. Velasquez ◽  
M. M. Ricardi ◽  
J. G. Dorosz ◽  
P. V. Fernandez ◽  
A. D. Nadra ◽  
...  
Keyword(s):  
Cell Wall ◽  
Root Hair ◽  
Hair Growth ◽  
Cell Wall Proteins ◽  
Root Hair Growth

scholarly journals NAC transcription factor RD26 is a regulator of root hair morphogenic plasticity

2021 ◽  
Author(s):  
Iman Kamranfar ◽  
Salma Balazadeh ◽  
Bernd Mueller-Roeber
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Drought Stress ◽  
Root Hair ◽  
Regulatory Network ◽  
Hair Growth ◽  
Root Hairs ◽  
Nac Transcription Factor ◽  
Numerous Cell ◽  
Root Hair Growth

AbstractRoot hairs are outgrowths of epidermal cells central for water and nutrient acquisition. Root hair growth is plastically modified by environmental cues. A frequent response to water limitation is active shortening of root hairs, involving largely unknown molecular mechanisms. A root hair-specific cis-regulatory element (RHE) integrates developmental cues with downstream signalling of root hair morphogenesis. Here, we demonstrate NAC transcription factor RD26 to be a key expressional regulator of this drought stress-triggered developmental response in Arabidopsis thaliana. RD26 directly represses RSL4 and RSL1, two master transcription regulators of root hair morphogenesis, by binding RHE. RD26 further represses core cell wall modification genes including expansins (EXPA7, EXPA18), hydroxyproline-rich glycoproteins (LRX1), xyloglucan endotransglucosylases/hydrolases (XTH12, 13, 14, 26), class III peroxidases (PRX44) and plasma membrane H+-ATPase (AHA7) through RHE. Of note, several RD26-repressed genes are activated by RSL4. Thus, by repressing RSL4 and numerous cell wall-related genes, RD26 governs a robust gene regulatory network for restricting root hair growth under drought. A similar regulatory network exists in tomato, indicating evolutionary conservation across species.Significance statementIn plants, root hairs play a vital role for water and nutrient acquisition, soil anchorage, and microbial interactions. During drought stress, root hair growth is suppressed as an adaptive strategy to save cellular energy. We identified NAC transcription factor RD26 as a key regulator of this developmental plasticity in the model plant Arabidopsis thaliana. RD26 directly and negatively controls the transcriptional activity of key root hair developmental genes, RSL1 and RSL4. Furthermore, RD26 suppresses the expression of several functional genes underlying root hair development including numerous cell wall-related genes. RD26 thus governs a robust gene regulatory network underlying the developmental response to drought stress. A similar regulatory network exists in tomato indicating evolutionary conservation of this mechanism across species.

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