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regulation of root hair initiation and expansin gene expression in arabidopsisThe expression of two Arabidopsis expansin genes (AtEXP7 and AtEXP18) is tightly linked to root hair initiation; thus, the regulation of these genes was studied to elucidate how developmental, hormonal, and environmental factors orchestrate root hair formation. Exogenous ethylene and auxin, as well as separation of the root from the medium, stimulated root hair formation and the expression of these expansin genes. The effects of exogenous auxin and root separation on root hair formation required the ethylene signaling pathway. By contrast, blocking the endogenous ethylene pathway, either by genetic mutations or by a chemical inhibitor, did not affect normal root hair formation and expansin gene expression. These results indicate that the normal developmental pathway for root hair formation (i.e., not induced by external stimuli) is independent of the ethylene pathway. Promoter analyses of the expansin genes show that the same promoter elements that determine cell specificity also determine inducibility by ethylene, auxin, and root separation. Our study suggests that two distinctive signaling pathways, one developmental and the other environmental/hormonal, converge to modulate the initiation of the root hair and the expression of its specific expansin gene set.
Document ID
20040087951
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Cho, Hyung-Taeg
(University Park Pennsylvania 16802, United States)
Cosgrove, Daniel J.
Date Acquired
August 21, 2013
Publication Date
December 1, 2002
Publication Information
Publication: The Plant cell
Volume: 14
Issue: 12
ISSN: 1040-4651
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Plant Biology
NASA Program Fundamental Space Biology
Non-NASA Center