In the newly founded German-Chinese Joint Research Center of Plant Biotechnology between the University of Freiburg (Germany) and the Shandong Agricultural University (P.R.China), we are seeking highly motivated candidates to investigate the epigenetic regulation of plant stem cells in the working team of Professor Thomas Laux. The position is initially for three years with the potential for extension and the application is open until a suitable candidate has been found. The candidate has a strong background in developmental genetics and molecular biology with specific expertise in genomic bioinformatic analysis and epigenetic methods. The successful candidate has an excellent track record, is highly motivated to work in an international team, and is prepared to develop an own research profile leading a team of M.Sc. and PhD students in order to publishing in high-ranked journals. The majority of the work will be performed at Shandong Agricultural University with research stays at the University Freiburg. Both Universities have excellent platforms for molecular plant research, including live imaging, high-throughput analysis, synthetic biology, and agricultural development. To apply, please send your CV including your research experiences and your research interests to Thomas Laux (
[email protected]). For more information on the Laux research team, please visit
http://www.biologie.uni-freiburg.de/LauxLab/.
Goal of the project: Understand how the genetic and epigenetic networks regulate columella stem cells in the root with a specific focus on the interaction between stem cells and the environment. A specific focus will be on the epigenetic regulation of stem cells during this process that we previously discovered (A). In addition to standard genetic and molecular tools, the projects utilize a novel microfluidic technology that is developed together with our engineering partners (B).
(A) Diagram of the root stem cell niche (left). Stem cell are epigenetically regulated by the mobile transcription factor WOX5. For details see our publications: Pi et al., 2015, Dev Cell 33, 576; Sarkar et al., 2007, Nature 446, 811. (B) Microfluidic system to study adaptation of stem cell regulation to environmental conditions.
Background: Unlike most animals, plants can grow and form new organs throughout their life, which in the case of some long-lived trees can last for more than thousand year. The cells for this are supplied by pluripotent stem cells in the proliferative centers plants, the meristems. In addition to their longevity, plant growth and thus stem cell activity must adjust to environmental signals, such as season, light, water and nutrient supply.
Our group previously has shown that the stem cells of the shoot meristem are regulated by a negative feedback loop between the transcription factor WUSCHEL (WUS) and the signaling peptide CLAVATA3 (Mayer at al., Cell 1998; Schoof et al., Cell 2000). This feedback look is initiated by a mechanisms balancing phytohormone action (Zhang et al., Dev. Cell 2017) and integrates positional information from surrounding cells (Knauer et al., Dev. Cell 2013).
We also found that the root meristem functions in a similar way, expressing the WUS homolog WOX5 (Sarkar et al., Nature 2007). WOX5 is required to maintain the stem cells forming the gravity sensing columella pluripotent. WOX5 functions as an epigenetic regulator, that changes the chromatin of the stem cells by recruiting a histone modifying enzyme to the DNA of its target genes, and as consequence, the Chromatin becomes compacted and the genes silenced (Pi et al., Dev. Cell, 2015). Ectopic expression of WOX5 can reprogram already differentiated cell into induced pluripotent stem cells (iPS), providing a powerful tool to study stem cell biology that will be used in this project. The root stem cells must adapt to a number of abiotic and biotic environmental challenges including drought, flooding, nutrient shortage, soil contamination but also bacteria and fungus infections. How active stem cells can be maintained for such a long time and accurately form new organs and how they can sense and adapt to environmental conditions is a central question for both, stem cell biology and agriculture.
