lnu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
WOX2 and polar auxin transport during spruce embryo pattern formation
University of Kalmar, School of Pure and Applied Natural Sciences. (Inger Hakman)
University of Kalmar, School of Pure and Applied Natural Sciences. (Hakman)
2009 (English)In: Plant Signalling & Behavior, ISSN 1559-2316, E-ISSN 1559-2324, Vol. 4, no 2, p. 153-155Article in journal (Other academic) Published
Abstract [en]

The WOX family of transcription factors and polar auxin transport (PAT) are both essential for embryonic patterning and thus normal embryo development in angiosperms. Recent analysis by us of WOX-related genes in Picea and Pinus suggests that they play fundamental roles during embryo development also in conifers.1 It has been proposed that there is a connection between the spatial separation of WOX2 and WOX8, and PAT in the formation of the apical-basal axis in Arabidopsis embryos and that both are involved in the regulation of the auxin efflux carrier PIN1. Auxin also seems to play a crucial role in apical-basal axis formation in conifer embryos based on studies using the polar auxin inhibitor NPA. We recently analyzed the expression of a PIN1-like gene in NPA-treated and untreated precotyledonary somatic spruce embryos and could see a significant upregulation of the PIN1-like gene in the NPA-treated embryos.2 Here we show that PaWOX2 is also significantly upregulated in the same embryos. Taken together, this suggests that PAT is involved in regulating both PIN1 and WOX2 expression in conifers and strengthens the evidence for the proposed connection between WOX and PIN genes in seed plants.

Place, publisher, year, edition, pages
Landes Biosciences , 2009. Vol. 4, no 2, p. 153-155
Keywords [en]
conifer, Picea abies, embryo development, polar auxin transport, WOX, PIN, NPA, somatic embryogenesis, qRT-PCR
National Category
Botany
Research subject
Natural Science, Cell and Organism Biology
Identifiers
URN: urn:nbn:se:hik:diva-2927DOI: 10.4161/psb.4.2.7684OAI: oai:DiVA.org:hik-2927DiVA, id: diva2:300812
Available from: 2010-03-01 Created: 2010-03-01 Last updated: 2017-12-12Bibliographically approved
In thesis
1. Conifer embryology: a study of polar auxin transport and WOX transcription factors
Open this publication in new window or tab >>Conifer embryology: a study of polar auxin transport and WOX transcription factors
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Plants, like animals, use endogenous signaling molecules to coordinate their own physiology and development. One such molecule in plants is the hormone auxin and recent research has implicated auxin and its polar transport, together with the WOX transcription factors, in regulating embryo patterning and development in angiosperms (flowering plants), the most diverse group of land plants. No extensive investigation of this has been carried out on the more evolutionary distant gymnosperms, the other major taxa of seed plants. Thus, in this thesis I, together with my co-authors, have analyzed the regulation of embryonic pattern formation in the coniferous gymnosperm Picea abies (Norway spruce) using seed and somatic embryos. Conifers are important forestry species and knowledge of their embryology is vital for reforestration programs, where the method of somatic embryogenesis is employed for mass propagation as well as it is used as a model system for embryo development.

Mature spruce embryos display a basic body plan and contain a shoot apical meristem (SAM), cotyledons, hypocotyl, embryonic root and a root apical meristem (RAM), with the meristems generating differentiated cells for organ formation. Treatment of embryos with a polar auxin transport (PAT) inhibitor produce embryos with poor SAM and, in some cases, fused cotyledons. Thus, PAT is essential for the correct patterning of conifer embryos. In angiosperms, PAT is mainly established and maintained by members of the auxin efflux facilitator PIN-FORMED (PIN) family. I isolated a PIN homologue (PaPIN1), of high abundance in conifer tissues, that is localized, together with auxin, to the epidermis of precotyledonary spruce embryos and upregulated as well as delocalized from the epidermis in early PAT inhibited embryos. Since also auxin concentration seems to decrease in the epidermis of these embryos, my data indicate that local auxin accumulation in the epidermis is mediated by PIN-dependent auxin transport.

Further, I investigated WOX genes in conifers and isolated two homologues, PaWOX2 and PaWOX8/9, that are expressed throughout spruce embryo development. Their expression profile suggests involvement in cell proliferation and specification, and, indeed, they both serve as markers for conifer somatic embryogenesis. The expression of PaWOX2 and PaWOX8/9 overlap with PaPIN1 in differentiating vascular tissue (procambium) of spruce embryos and is also upregulated in early PAT inhibited embryos. Thus, PaWOX2, PaWOX8/9, and PaPIN1 may all act together in procambium differentiation. With this, I conclude that a common mechanism, involving PAT and WOX, regulate embryo pattern formation in seed plants. Results in post-embryonic tissue imply a common mechanism regulating pattern formation also here.

Place, publisher, year, edition, pages
Kalmar/Växjö: Linnaeus University Press, 2010
Series
Linnaeus University Dissertations ; 10/2010
National Category
Botany
Research subject
Natural Science, Cell and Organism Biology
Identifiers
urn:nbn:se:hik:diva-2932 (URN)978-91-86491-12-3 (ISBN)
Public defence
2010-04-16, Hörsalen Fullrigaren, Landgången 4, Kalmar, 09:30 (English)
Opponent
Supervisors
Available from: 2010-04-09 Created: 2010-03-01 Last updated: 2014-05-12Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full texthttp://www.landesbioscience.com/journals/10/article/7684/

Authority records BETA

Palovaara, JoakimHakman, Inger

Search in DiVA

By author/editor
Palovaara, JoakimHakman, Inger
By organisation
School of Pure and Applied Natural Sciences
In the same journal
Plant Signalling & Behavior
Botany

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 116 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf