Jens Keilwagen

Publications (2)14.19 Total impact

• Article: Toward the identification and regulation of the Arabidopsis thaliana ABI3 regulon.

  Gudrun Mönke, Michael Seifert, Jens Keilwagen, Michaela Mohr, Ivo Grosse, Urs Hähnel, Astrid Junker, Bernd Weisshaar, Udo Conrad, Helmut Bäumlein, Lothar Altschmied
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  ABSTRACT: The plant-specific, B3 domain-containing transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3) is an essential component of the regulatory network controlling the development and maturation of the Arabidopsis thaliana seed. Genome-wide chromatin immunoprecipitation (ChIP-chip), transcriptome analysis, quantitative reverse transcriptase-polymerase chain reaction and a transient promoter activation assay have been combined to identify a set of 98 ABI3 target genes. Most of these presumptive ABI3 targets require the presence of abscisic acid for their activation and are specifically expressed during seed maturation. ABI3 target promoters are enriched for G-box-like and RY-like elements. The general occurrence of these cis motifs in non-ABI3 target promoters suggests the existence of as yet unidentified regulatory signals, some of which may be associated with epigenetic control. Several members of the ABI3 regulon are also regulated by other transcription factors, including the seed-specific, B3 domain-containing FUS3 and LEC2. The data strengthen and extend the notion that ABI3 is essential for the protection of embryonic structures from desiccation and raise pertinent questions regarding the specificity of promoter recognition.
  Nucleic Acids Research 06/2012; 40(17):8240-54. · 8.03 Impact Factor
• Article: Elongation-related functions of LEAFY COTYLEDON1 during the development of Arabidopsis thaliana.

  Astrid Junker, Gudrun Mönke, Twan Rutten, Jens Keilwagen, Michael Seifert, Tuyet Minh Nguyen Thi, Jean-Pierre Renou, Sandrine Balzergue, Prisca Viehöver, Urs Hähnel, Jutta Ludwig-Müller, Lothar Altschmied, Udo Conrad, Bernd Weisshaar, Helmut Bäumlein
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  ABSTRACT: The transcription factor LEAFY COTYLEDON1 (LEC1) controls aspects of early embryogenesis and seed maturation in Arabidopsis thaliana. To identify components of the LEC1 regulon, transgenic plants were derived in which LEC1 expression was inducible by dexamethasone treatment. The cotyledon-like leaves and swollen root tips developed by these plants contained seed-storage compounds and resemble the phenotypes produced by increased auxin levels. In agreement with this, LEC1 was found to mediate up-regulation of the auxin synthesis gene YUCCA10. Auxin accumulated primarily in the elongation zone at the root-hypocotyl junction (collet). This accumulation correlates with hypocotyl growth, which is either inhibited in LEC1-induced embryonic seedlings or stimulated in the LEC1-induced long-hypocotyl phenotype, therefore resembling etiolated seedlings. Chromatin immunoprecipitation analysis revealed a number of phytohormone- and elongation-related genes among the putative LEC1 target genes. LEC1 appears to be an integrator of various regulatory events, involving the transcription factor itself as well as light and hormone signalling, especially during somatic and early zygotic embryogenesis. Furthermore, the data suggest non-embryonic functions for LEC1 during post-germinative etiolation.
  The Plant Journal 03/2012; 71(3):427-42. · 6.16 Impact Factor