dc.contributor.advisor | Dröge-Laser, Wolfgang Prof. Dr. | de |
dc.contributor.author | Weiste, Christoph | de |
dc.date.accessioned | 2013-01-14T15:07:30Z | de |
dc.date.available | 2013-01-30T23:50:52Z | de |
dc.date.issued | 2012-04-10 | de |
dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-000D-EF53-3 | de |
dc.identifier.uri | http://dx.doi.org/10.53846/goediss-1478 | |
dc.format.mimetype | application/pdf | de |
dc.language.iso | eng | de |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/ | de |
dc.title | Arabidopsis basic leucine Zipper transcription factors function as quantitative modulators of auxin mediated transcription | de |
dc.type | doctoralThesis | de |
dc.title.translated | Arabidopsis bZIP Transkriptionsfaktoren modulieren quantitativ die Auxin-vermittelte Transkription | de |
dc.contributor.referee | Dröge-Laser, Wolfgang Prof. Dr. | de |
dc.date.examination | 2011-04-26 | de |
dc.subject.dnb | 570 Biowissenschaften, Biologie | de |
dc.subject.gok | WF200 | de |
dc.description.abstracteng | The essential plant growth hormone auxin
orchestrates a wide range of developmental and environmental
processes in the course of plant life. In general, these responses
are predominately implemented by the encoded activity of auxin
responsive genes, which are corporately regulated by the family of
Auxin Response Factors (ARFs) and the class of AUX/IAA proteins.
Whereas ARF transcription factors (TFs) exert their
trans-activating properties upon direct binding to their cognate
Auxin Response Elements (AuxREs), the AUX/IAA transcriptional
repressors contact the ARF proteins to modulate their activity. In
order to sustain optimal plant growth, auxin mediated responses
have to be adjusted according to the prevailing endogenous and
environmental conditions. Thus an integration of the corresponding
stimuli into auxin-related transcriptional patterns is required.
Bioinformatic promoter cis-element analyses revealed that promoters
of auxin responsive genes are not only significantlyenriched for
AuxREs, but also for the G-BOX RELATED ELEMENTS (GREs) and MYB
RESPONSIVE ELEMENTS (MREs). Using the Arabidopsis AtGH3.3 promoter
as an auxin responsive model system, a combinatorial control of
auxin-mediated transcription by a complex arrangement of these, in
part redundantly acting, cis-elements has been demonstrated.
Whereas AuxREs function as auxin-dependent switches, GREs and MREs
act as quantitative modulators. Applying a trans-activation
screening approach in protoplasts, members of the C/S1 network of
basic leucine zipper (bZIP) TFs have been identified, which enhance
and sensitize auxin-mediated transcription via binding the GRE
cis-element. Complementary, gain- and loss-of-function approaches
in transgenic plants confirm that the closely related group S1
AtbZIP2, -11 and -44 TFs modulate auxin-induced transcription and
are capable to alter typical auxin-related growth-responses, such
as primary root growth, lateral root formation, root hair density
and gravitropism. Histochemical expression analysis of the auxin
respon sive DR5:GFP reporter suggests bZIP-dependent alterations in
auxin distribution and/or signalling. Ensuing studies on the
mechanistical action of the group S1 bZIPs on auxin mediated
transcription revealed that particularly AtbZIP11-related TFs are
able to recruit the SAGA-like acetylation machinery via their
N-terminal activation domain. Pharmacological and reverse genetic
approaches clearly define the impact of histone acetylation in
auxin-induced transcription. In fact, Chromatin-Immunoprecipitation
(ChIP) analyses confirm bZIP-dependent recruitment of the histone
acetylation machinery and RNA-Polymerase II. Altogether, these data
suggest a novel bZIP-mediated mechanism to fine-tune chromatin
accessibility during auxin-induced gene activation. As C/S1
bZIP-TFs are reprogramming the primary metabolism in response to
energy stress, the GRE/bZIP module might function as a
“rheostat | de |
dc.contributor.coReferee | Gatz, Christiane Prof. Dr. | de |
dc.subject.topic | Biology (incl. Psychology) | de |
dc.subject.ger | Auxin | de |
dc.subject.ger | Genregulation | de |
dc.subject.ger | bZIP | de |
dc.subject.ger | Transkriptionsfaktor | de |
dc.subject.eng | Auxin | de |
dc.subject.eng | gene-regulation | de |
dc.subject.eng | bZIP | de |
dc.subject.eng | transcriptionfactor | de |
dc.subject.bk | 42.42 | de |
dc.identifier.urn | urn:nbn:de:gbv:7-webdoc-3456-2 | de |
dc.identifier.purl | webdoc-3456 | de |
dc.affiliation.institute | Biologische Fakultät | de |
dc.identifier.ppn | 715204238 | de |