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Auxin Dynamics after Decapitation Are Not Correlated with the Initial Growth of Axillary Buds


Morris, SE and Cox, MCH and Ross, JJ and Krisantini, S and Beveridge, CA, Auxin Dynamics after Decapitation Are Not Correlated with the Initial Growth of Axillary Buds, Plant Physiology, 138, (3) pp. 1665-1672. ISSN 0032-0889 (2005) [Refereed Article]

DOI: doi:10.1104/pp.104.058743


One of the first and most enduring roles identified for the plant hormone auxin is the mediation of apical dominance. Many reports have claimed that reduced stem indole-3-acetic acid (IAA) levels and/or reduced basipetal IAA transport directly or indirectly initiate bud growth in decapitated plants. We have tested whether auxin inhibits the initial stage of bud release, or subsequent stages, in garden pea (Pisum sativum) by providing a rigorous examination of the dynamics of auxin level, auxin transport, and axillary bud growth. We demonstrate that after decapitation, initial bud growth occurs prior to changes in IAA level or transport in surrounding stem tissue and is not prevented by an acropetal supply of exogenous auxin. We also show that auxin transport inhibitors cause a similar auxin depletion as decapitation, but do not stimulate bud growth within our experimental time-frame. These results indicate that decapitation may trigger initial bud growth via an auxin-independent mechanism. We propose that auxin operates after this initial stage, mediating apical dominance via autoregulation of buds that are already in transition toward sustained growth. © 2005 American Society of Plant Biologists.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Environmentally sustainable plant production
Objective Field:Environmentally sustainable plant production not elsewhere classified
UTAS Author:Ross, JJ (Associate Professor John Ross)
ID Code:36119
Year Published:2005
Web of Science® Times Cited:84
Deposited By:Plant Science
Deposited On:2005-08-01
Last Modified:2006-05-09

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