General overview of our research area
We are interested in the biochemistry and physiology of plant metabolism. Currently, we are focusing on the metabolism of vitamin compounds. Vitamins were first discovered, almost a century ago, as vital nutrients that must be taken in the human diet. Yet, it is remarkable that after all this time, we are still not fully aware of how these essential compounds are synthesized in our most important source of them, plants. This is particularly apparent for some of the B complex vitamins, e.g. B1 and B6. Moreover, because this knowledge has been lacking, albeit until relatively recently in the case of vitamin B6, it was not known what effect these compounds have on plants themselves. The onset of the genomic era and the numerous molecular tools currently available to the community (especially for the plant model Arabidopsis thaliana) make this kind of research feasible. On the one hand, while there is a fundamental interest in how these molecules are biosynthesized, there is also considerable attention given to their modes of regulation and transport. For example, the relevance of RNA had long been restricted to the translation of genetic information from DNA to proteins. The emerging awareness of the role of RNA, e.g. riboswitches, in gene control has changed this view dramatically. Riboswitches in particular have an enormous untapped potential and are predestined to act as an archetype for the development of artificial regulators and nanosensors. Metabolite transport is also an aspect of plant metabolism that is still far from completion. Although the transport of metabolites can be inferred from the location of the enzymes of the pathway, many of the proteins involved in membrane transport and intracellular trafficking have not yet been identified. Part of our research is dedicated to unraveling these mechanisms in plants. Another area of interest in our laboratory is that the absence of vitamin biosynthesis pathways from animals, means that enzymes specific to the routes may serve as novel antimicrobial or herbicide agents. In addition, many of the reactions involved in the biosynthesis of these compounds involve unprecedented chemistry and have not been reconstituted in vitro. While it is relatively easy to identify mutations in genes involved, it is considerably more difficult to identify the specific reaction being catalyzed by the respective protein. This large gap of knowledge between sequence information and function of enzymes involved in biosynthetic pathways, involving unprecedented reactions, is a major challenge in the field of functional genomics. Thus, we also strive to characterize the biochemical and biophysical aspects of the various proteins involved in these pathways. Various model organisms are employed in our laboratory, namely the Gram-positive bacterium, Bacillus subtilis, the budding yeast Saccharomyces cerevisiae and the plant model Arabidopsis thaliana.
Furthermore, the elucidation of the biosynthesis and regulatory networks may lead to the possibility of overproduction of these compounds for beneficial effects. For example, recent findings suggest that the vitamin B complex appears to have substantial roles in various stress responses. In particular, vitamin B6 is reported to be an antioxidant with potency equivalent to vitamins C and E. Thus, another part of our work focuses on understanding the antioxidant properties of vitamin B6 as well as clarifying its role in plant defense, which will be of value in the development of stress tolerant crops.
Due to the nature of our research a vast array of methods are employed in the laboratory, ranging from techniques in molecular biology, cell biology, genetics, and protein biochemistry to certain biophysical procedures.