This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 148/3/1453    most recent pp.108.125385v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Maes, L. Articles by Goossens, A. Search for Related Content PubMed PubMed Citation Articles by Maes, L. Articles by Goossens, A. Agricola Articles by Maes, L. Articles by Goossens, A.

DEVELOPMENT AND HORMONE ACTION

Functional Specialization of the TRANSPARENT TESTA GLABRA1 Network Allows Differential Hormonal Control of Laminal and Marginal Trichome Initiation in Arabidopsis Rosette Leaves^1,[W]

Department of Plant Systems Biology, Flanders Institute for Biotechnology and Department of Molecular Genetics, Ghent University, 9052 Ghent, Belgium

Trichome initiation in Arabidopsis (Arabidopsis thaliana) is controlled by the TRANSPARENT TESTA GLABRA1 (TTG1) network that consists of R2R3- and R1-type MYB-related transcription factors, basic helix-loop-helix (bHLH) proteins, and the WD40 protein TTG1. An experimental method was designed to investigate the molecular mechanisms by which jasmonates, cytokinins, and gibberellins modulate Arabidopsis leaf trichome formation. All three phytohormones provoked a seemingly common effect on cell patterning by promoting trichome initiation but caused strikingly distinct effects on cell and trichome maturation. The phytohormonal control was mediated by transcriptional regulation of the established TTG1 complex and depended on the R2R3-MYB factor GLABRA1. However, unsuspected degrees of functional specialization of the bHLH factors and a resultant differential molecular regulation of trichome initiation on leaf lamina and leaf margins were revealed. Trichome formation on leaf lamina relied entirely on GLABRA3 and ENHANCER OF GLABRA3. Conversely, TRANSPARENT TESTA8 (TT8) was particularly important for marginal trichome development. This hitherto unknown role for TT8 in trichome formation further underscored the functional redundancy between the three TTG1-dependent bHLH proteins.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Alain Goossens (algoo{at}psb.ugent.be).

^[W] The online version of this article contains Web-only data.

www.plantphysiol.org/cgi/doi/10.1104/pp.108.125385

^* Corresponding author; e-mail algoo{at}psb.ugent.be.

Received June 26, 2008; accepted September 7, 2008; published September 10, 2008.

This article has been cited by other articles:

				Y. Yoshida, R. Sano, T. Wada, J. Takabayashi, and K. Okada Jasmonic acid control of GLABRA3 links inducible defense and trichome patterning in Arabidopsis Development, March 15, 2009; 136(6): 1039 - 1048. [Abstract] [Full Text] [PDF]