SNARE VTI13 plays a unique role in endosomal trafficking pathways associated with the vacuole and is essential for cell wall organization and root hair growth in arabidopsis

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.

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Faculty Opinions recommendation of O-glycosylated cell wall proteins are essential in root hair growth.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.11653956.12722054 ◽

2011 ◽

Author(s):

Antoni Rafalski ◽

Kanwarpal Dhugga

Keyword(s):

Cell Wall ◽

Root Hair ◽

Hair Growth ◽

Cell Wall Proteins ◽

Root Hair Growth

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

10.1101/2021.04.21.440803 ◽

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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Faculty Opinions recommendation of A protein kinase target of a PDK1 signalling pathway is involved in root hair growth in Arabidopsis.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1020408.234459 ◽

2004 ◽

Author(s):

Jen Sheen

Keyword(s):

Protein Kinase ◽

Root Hair ◽

Hair Growth ◽

Signalling Pathway ◽

Root Hair Growth

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MYB30 and ETHYLENE INSENEITIVE3 antagonistically regulate root hair growth and phosphorus uptake under phosphate deficiency in Arabidopsis

Plant Signaling & Behavior ◽

10.1080/15592324.2021.1913310 ◽

2021 ◽

pp. 1913310

Author(s):

Fei Xiao ◽

Yiyi Zhang ◽

Shuangshuang Zhao ◽

Huapeng Zhou

Keyword(s):

Root Hair ◽

Hair Growth ◽

Phosphorus Uptake ◽

Phosphate Deficiency ◽

Root Hair Growth

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The TOR–Auxin Connection Upstream of Root Hair Growth

Plants ◽

10.3390/plants10010150 ◽

2021 ◽

Vol 10 (1) ◽

pp. 150 ◽

Cited By ~ 1

Author(s):

Katarzyna Retzer ◽

Wolfram Weckwerth

Keyword(s):

Cell Fate ◽

Root Hair ◽

Hair Growth ◽

Environmental Changes ◽

Growth Control ◽

Root Hairs ◽

Signaling Cascades ◽

Continuous Growth ◽

Root Hair Cell ◽

Root Hair Growth

Plant growth and productivity are orchestrated by a network of signaling cascades involved in balancing responses to perceived environmental changes with resource availability. Vascular plants are divided into the shoot, an aboveground organ where sugar is synthesized, and the underground located root. Continuous growth requires the generation of energy in the form of carbohydrates in the leaves upon photosynthesis and uptake of nutrients and water through root hairs. Root hair outgrowth depends on the overall condition of the plant and its energy level must be high enough to maintain root growth. TARGET OF RAPAMYCIN (TOR)-mediated signaling cascades serve as a hub to evaluate which resources are needed to respond to external stimuli and which are available to maintain proper plant adaptation. Root hair growth further requires appropriate distribution of the phytohormone auxin, which primes root hair cell fate and triggers root hair elongation. Auxin is transported in an active, directed manner by a plasma membrane located carrier. The auxin efflux carrier PIN-FORMED 2 is necessary to transport auxin to root hair cells, followed by subcellular rearrangements involved in root hair outgrowth. This review presents an overview of events upstream and downstream of PIN2 action, which are involved in root hair growth control.

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