Change search
ReferencesLink to record
Permanent link

Direct link
Transcriptional and hormonal regulation of gravitropism of woody stems in populus
Show others and affiliations
2015 (English)In: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 27, no 10, 2800-2813 p.Article in journal (Refereed) PublishedText
Abstract [en]

Angiosperm trees reorient their woody stems by asymmetrically producing a specialized xylem tissue, tension wood, which exerts a strong contractile force resulting in negative gravitropism of the stem. Here, we show, in Populus trees, that initial gravity perception and response occurs in specialized cells through sedimentation of starch-filled amyloplasts and relocalization of the auxin transport protein, PIN3. Gibberellic acid treatment stimulates the rate of tension wood formation and gravibending and enhances tissue-specific expression of an auxin-responsive reporter. Gravibending, maturation of contractile fibers, and gibberellic acid (GA) stimulation of tension wood formation are all sensitive to transcript levels of the Class I KNOX homeodomain transcription factor-encoding gene ARBORKNOX2 (ARK2). We generated genome-wide transcriptomes for trees in which gene expression was perturbed by gravistimulation, GA treatment, and modulation of ARK2 expression. These data were employed in computational analyses to model the transcriptional networks underlying wood formation, including identification and dissection of gene coexpression modules associated with wood phenotypes, GA response, and ARK2 binding to genes within modules. We propose a model for gravitropism in the woody stem in which the peripheral location of PIN3-expressing cells relative to the cambium results in auxin transport toward the cambium in the top of the stem, triggering tension wood formation, while transport away from the cambium in the bottom of the stem triggers opposite wood formation.

Place, publisher, year, edition, pages
American Society of Plant Biologists , 2015. Vol. 27, no 10, 2800-2813 p.
National Category
Plant Biotechnology Cell Biology
URN: urn:nbn:se:kth:diva-181251DOI: 10.1105/tpc.15.00531ISI: 000368293600016ScopusID: 2-s2.0-84946782272OAI: diva2:901628
National Board of Housing, Building and Planning

Funding Details: NNX09AK82G, NASA, National Aeronautics and Space Administration

QC 20160208

Available from: 2016-02-08 Created: 2016-01-29 Last updated: 2016-02-24Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Ibatullin, Farid M.Brumer, Harry
By organisation
In the same journal
The Plant Cell
Plant BiotechnologyCell Biology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 24 hits
ReferencesLink to record
Permanent link

Direct link