Markus Frank

Lehrstuhl für Allgemeine Genetik
Auf der Morgenstelle 28
72076 Tübingen
Germany

Tel. 07071 / 2974608
Fax. 07071 / 295042

Research Interests

Genetic and molecular characterization of plant cell differentiation in vitro

Cell division, growth and differentiation need to be precisley controlled during development of the plant. Different tissues have to fullfill different functions. In the meristems for instance the most cell divisions take place while suppressed in other somatic tissues. Loss of control will lead to cell division and growth at ectopic positions and often the formation of plant tumors.
There is a large body of evidence that tumor formation and tumor growth are often caused by or linked to imbalances of hormone contents or to changes in hormone sensitivity. Also the decision what type of organ that can be formed by a tumor is made under the regime of hormone content.

Furthermore, recent results support the hypothesis that the deregulation of or mutation of other elements such as plant homologs of tumor suppressor genes or genes for their target proteins, genes for cell cycle regulators, genes encoding intracellular signal transducers and transcription factors like homeobox genes can be intimately linked or causally related to the observed phenotype.

The goal of this project is the isolation and characterization of Arabidopsis mutant lines exhibiting fundamental disturbances in differentiation in vitro. Therefore, EMS-, T-DNA- and Transopson-induced mutant lines are screened for abnormal phenotypes on hormone-free medium. The finding of a tagged locus will greatly facilitate gene cloning.
In order to classify the mutant phenotypes the expression of marker genes like hormone signal transducers, homeobox genes, cell cycle regulators and tumor suppressor homologs are examined. These results are flanked with other morphological and physiological parameters. The hormone contents of the mutant lines are measured in a collaboration with Dr. Miroslav Strnad, Olomouc, and Prof. Dr. Harry van Onckelen, Antwerp.

The genetic and molecular characterization of Arabidopsis differentiation mutant lines should contribute to a better understanding of the regulation of plant cell division, growth and differentiation.

This work is kindly supported by a fellowship of Studienstiftung des deutschen Volkes.