Dr. Rainer E. Häusler
University of Cologne
Zülpicher Str. 47b
Phone: +221 470 2340
Understanding the Regulation of Plant Metabolism
Plant metabolism and its regulation is complex and still far from being completely understood. There is a bulk of information available in world-wide databases to date concerning the structure of genes and their putative functions. The successful completion of sequencing whole genomes of prokaryotes and eukaryotes, amongst them the genome of the model plant Arabidopsis thaliana or the crop plant rice and others, opens the way to large-scale approaches.
Apart from large-scale approaches, which are essential and necessary in order to deal with the whole system as such and to decrease the size of patches in the fabric of a giant patchwork, I think it is still possible to gather interesting and new information using the already existing and well defined sources of transgenic and mutant plants. In many cases a perturbation of metabolism will lead to pleiotropic changes in gene expression and compensatory mechanisms are installed. However, compensatory changes in plant performance can be used as a tool to gain additional information on the fine tuning of metabolic regulation inevitable to fully comprehend its complexity.
Currently my interest is focused on mutant and transgenic plants with lesions in or altered activities of plastidial metabolite transporters. Of particular interest are Arabidopsis thaliana mutants with modified allocation of photoassimilates (defect in the triose phosphate/phosphate translocator) or an impairment of mesophyll development (lesion in a phosphoenolpyruvate/phosphate translocator). The functional role of the xylulose-5-phosphate/phosphate translocator (XPT) is still obscure and efforts are on the way to fill this gap.
I am still interested in attempts to install a single cell C4-metabolism in C3 crops.