Ethylene is an endogenous stimulator of cell division in the cambial meristem of Populus
- Jonathan Lovea,1,
- Simon Björklunda,1,
- Jorma Vahalab,
- Magnus Hertzbergc,
- Jaakko Kangasjärvib and
- Björn Sundberga,2
- aUmeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183 Umeå, Sweden;
- bDepartment of Biological and Environmental Sciences, University of Helsinki, FI-00014, Helsinki, Finland; and
- cSweTree Technologies AB, Skogsmarksgränd 7, SE-90403 Umeå, Sweden
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Edited by Ronald R. Sederoff, North Carolina State University, Raleigh, NC, and approved February 2, 2009
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↵1J.L. and S.B. contributed equally to this work. (received for review November 16, 2008)
Abstract
The plant hormone ethylene is an important signal in plant growth responses to environmental cues. In vegetative growth, ethylene is generally considered as a regulator of cell expansion, but a role in the control of meristem growth has also been suggested based on pharmacological experiments and ethylene-overproducing mutants. In this study, we used transgenic ethylene-insensitive and ethylene-overproducing hybrid aspen (Populus tremula × tremuloides) in combination with experiments using an ethylene perception inhibitor [1-methylcyclopropene (1-MCP)] to demonstrate that endogenous ethylene produced in response to leaning stimulates cell division in the cambial meristem. This ethylene-controlled growth gives rise to the eccentricity of Populus stems that is formed in association with tension wood.
Footnotes
- 2To whom correspondence should be addressed. E-mail: bjorn.sundberg{at}genfys.slu.se
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Author contributions: J.L., S.B., J.V., M.H., J.K., and B.S. designed research; J.L., S.B., and J.V. performed research; J.L., S.B., J.V., and B.S. analyzed data; and J.L. and B.S. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0811660106/DCSupplemental.
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Freely available online through the PNAS open access option.
