Journal of Cell Science 116, e901 (2003)
Copyright © 2003 The Company of Biologists Limited
Stem cell regulation in shoots
Stem cells in the shoot meristem generate all aerial tissues in plants and
represent a good model system for studies of stem cell regulation in general.
Like all stem cells, these cells must strike a balance between self-renewal
and differentiation, and this is regulated by signals emanating from a group
of cells below termed the organizing centre (OC). In a Commentary on
p. 1659, Rita Groß-Hardt
and Thomas Laux review our understanding of these signals. Expression of the
secreted peptide CLAVATA 3 (CLV3) is a characteristic of stem cells in the
shoot meristem, and this is lost when they exit the stem cell pool. Genetic
and molecular studies have indicated that release of the homeodomain protein
WUS by cells in the OC drives CLV3 expression in the stem cells
above. They have also revealed a feedback loop in which CLV3 binds to
CLV1—CLV2 receptors in the OC and limits its size by activating a
signalling pathway that represses WUS expression. The existence of
this feedback loop allows the plant to define the physical boundaries of the
stem cell niche despite its constantly changing population.
Related articles in JCS:
- Stem cell regulation in the shoot meristem
- Rita Groß-Hardt and Thomas Laux
JCS 2003 116: 1659-1666.
[Abstract]
[Full Text]
