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Title: SHOOT MERISTEMLESS trafficking controls axillary meristem formation, meristem size and organ boundaries in Arabidopsis
Summary

The shoot stem cell niche, contained within the shoot apical meristem (SAM) is maintained in Arabidopsis by the homeodomain proteinSHOOT MERISTEMLESS(STM).STMis a mobile protein that traffics cell‐to‐cell, presumably through plasmodesmata. In maize, theSTMhomologKNOTTED1 shows clear differences betweenmRNAand protein localization domains in theSAM. However, theSTM mRNAand protein localization domains are not obviously different in Arabidopsis, and the functional relevance ofSTMmobility is unknown. Using a non‐mobile version ofSTM(2xNLSYFPSTM), we show thatSTMmobility is required to suppress axillary meristem formation during embryogenesis, to maintain meristem size, and to precisely specify organ boundaries throughout development.STMand organ boundary genesCUP SHAPED COTYLEDON1(CUC1),CUC2andCUC3regulate each other during embryogenesis to establish the embryonicSAMand to specify cotyledon boundaries, andSTMcontrolsCUCexpression post‐embryonically at organ boundary domains. We show that organ boundary specification by correct spatial expression ofCUCgenes requiresSTMmobility in the meristem. Our data suggest thatSTMmobility is critical for its normal function in shoot stem cell control.

 
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PAR ID:
10034204
Author(s) / Creator(s):
 ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
The Plant Journal
Volume:
90
Issue:
3
ISSN:
0960-7412
Page Range / eLocation ID:
p. 435-446
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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