In:
Development, The Company of Biologists, Vol. 135, No. 17 ( 2008-09-01), p. 2839-2843
Abstract:
Stem cells are maintained in an undifferentiated state by signals from their microenvironment, the stem cell niche. Despite its central role for organogenesis throughout the plant's life, little is known about how niche development is regulated in the Arabidopsis embryo. Here we show that, in the absence of functional ZWILLE (ZLL), which is a member of the ARGONAUTE (AGO) family, stem cell-specific expression of the signal peptide gene CLAVATA3 (CLV3) is not maintained despite increased levels of the homeodomain transcription factor WUSCHEL (WUS), which is expressed in the organising centre (OC) of the niche and normally promotes stem cell identity. Tissue-specific expression indicates that ZLLacts to maintain the stem cells from the neighbouring vascular primordium,providing direct evidence for a non-cell-autonomous mechanism. Furthermore,mutant and marker gene analyses suggest that during shoot meristem formation, ZLL functions in a similar manner but in a sequential order with its close homologue AGO1, which mediates RNA interference. Thus, WUS-dependent OC signalling to the stem cells is promoted by AGO1 and subsequently maintained by a provascular ZLL-dependent signalling pathway.
Type of Medium:
Online Resource
ISSN:
1477-9129
,
0950-1991
Language:
English
Publisher:
The Company of Biologists
Publication Date:
2008
detail.hit.zdb_id:
1411623-6
detail.hit.zdb_id:
2007916-3
SSG:
12
