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Mathematical modelling of WOX5- and CLE40-mediated columella stem cell homeostasis in Arabidopsis.

Richards S, Wink RH, Simon R - J. Exp. Bot. (2015)

Bottom Line: We have also found that WOX5 contributes to, but is not absolutely necessary for, CSC maintenance.Furthermore, our modelling led us to postulate an additional signalling molecule that promotes CSC maintenance.We propose that this WOX5-independent signal originates in the QC, is targeted by CLE40 signalling and is capable of maintaining CSCs.

View Article: PubMed Central - PubMed

Affiliation: Institute of Developmental Genetics, Heinrich Heine University, 40225 Düsseldorf, Germany.

No MeSH data available.


WOX5 signal and CLE40 peptide locations and their effect on CSC fate. WOX5 is expressed in the QC and signals to maintain CSCs distal to the QC. CLE40 is expressed in CCs, the differentiating daughters of the CSCs, and secreted into the apoplast, where it can act through plasma membrane-localized receptor-like kinases and inhibit the WOX5 signal. CCs are identifiable by their stainable starch granules.
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Figure 1: WOX5 signal and CLE40 peptide locations and their effect on CSC fate. WOX5 is expressed in the QC and signals to maintain CSCs distal to the QC. CLE40 is expressed in CCs, the differentiating daughters of the CSCs, and secreted into the apoplast, where it can act through plasma membrane-localized receptor-like kinases and inhibit the WOX5 signal. CCs are identifiable by their stainable starch granules.

Mentions: If the QC is ablated, the stem cells around it differentiate. The QC then reforms in a location proximal to the original QC site and a new stem cell niche is formed. This suggests that the surrounding stem cells are maintained by short-range signalling from the QC (van den Berg et al., 1997). The number and position of the CSCs are regulated by signals from both the QC and CCs. The QC expresses the transcription factor WUSCHEL-RELATED HOMEOBOX 5 (WOX5), which promotes CSC fate, while the CCs express and secrete the signalling peptide CLAVATA3/EMBRYO-SURROUNDING REGION 40 (CLE40) to encourage differentiation into CCs (Sarkar et al., 2007; Stahl et al., 2009). A typical wild-type Arabidopsis root has one layer of CSCs in the first layer distal to the QC (D1). The cells from D2 to the root tip have starch granules, the trait used to distinguish between CC and CSC identity (Fig. 1). It has been shown that constitutive expression of WOX5 results in massive accumulation of CSCs, while wox5-1 loss-of-function mutants typically have starch in the D1 layer. This suggested that WOX5 is both necessary and sufficient for CSC maintenance (Sarkar et al., 2007).


Mathematical modelling of WOX5- and CLE40-mediated columella stem cell homeostasis in Arabidopsis.

Richards S, Wink RH, Simon R - J. Exp. Bot. (2015)

WOX5 signal and CLE40 peptide locations and their effect on CSC fate. WOX5 is expressed in the QC and signals to maintain CSCs distal to the QC. CLE40 is expressed in CCs, the differentiating daughters of the CSCs, and secreted into the apoplast, where it can act through plasma membrane-localized receptor-like kinases and inhibit the WOX5 signal. CCs are identifiable by their stainable starch granules.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526915&req=5

Figure 1: WOX5 signal and CLE40 peptide locations and their effect on CSC fate. WOX5 is expressed in the QC and signals to maintain CSCs distal to the QC. CLE40 is expressed in CCs, the differentiating daughters of the CSCs, and secreted into the apoplast, where it can act through plasma membrane-localized receptor-like kinases and inhibit the WOX5 signal. CCs are identifiable by their stainable starch granules.
Mentions: If the QC is ablated, the stem cells around it differentiate. The QC then reforms in a location proximal to the original QC site and a new stem cell niche is formed. This suggests that the surrounding stem cells are maintained by short-range signalling from the QC (van den Berg et al., 1997). The number and position of the CSCs are regulated by signals from both the QC and CCs. The QC expresses the transcription factor WUSCHEL-RELATED HOMEOBOX 5 (WOX5), which promotes CSC fate, while the CCs express and secrete the signalling peptide CLAVATA3/EMBRYO-SURROUNDING REGION 40 (CLE40) to encourage differentiation into CCs (Sarkar et al., 2007; Stahl et al., 2009). A typical wild-type Arabidopsis root has one layer of CSCs in the first layer distal to the QC (D1). The cells from D2 to the root tip have starch granules, the trait used to distinguish between CC and CSC identity (Fig. 1). It has been shown that constitutive expression of WOX5 results in massive accumulation of CSCs, while wox5-1 loss-of-function mutants typically have starch in the D1 layer. This suggested that WOX5 is both necessary and sufficient for CSC maintenance (Sarkar et al., 2007).

Bottom Line: We have also found that WOX5 contributes to, but is not absolutely necessary for, CSC maintenance.Furthermore, our modelling led us to postulate an additional signalling molecule that promotes CSC maintenance.We propose that this WOX5-independent signal originates in the QC, is targeted by CLE40 signalling and is capable of maintaining CSCs.

View Article: PubMed Central - PubMed

Affiliation: Institute of Developmental Genetics, Heinrich Heine University, 40225 Düsseldorf, Germany.

No MeSH data available.