Isoprenoids form the largest class of plant secondary metabolites and approximately 40.000 compounds have been described. In plants, they influence the membrane structure (sterols), redox chemistry (plastoquinone, ubiquinone) and growth regulation (gibberellins, cytokinins, brassinosteroids and abscisic acid) or act in defence mechanisms (phytoalexins) and as scavengers of free radicals (carotenoids, tocopherols). Based on their natural functions many isoprenoids can be adapted for industrial uses. However, the content of secondary metabolites in plants is often limited and thus builds the overall research topic of our group.
Natural rubber is a unique high molecular weight biopolymer derived from plants. It consists of cis-1,4-polyisoprene with a molecular weight of about 106 g mol-1 and also contains a small percentage of substances (<1%) which contribute to the special properties of this polymer. It is characterized by elasticity, tensile strength and heat resistance, and cannot be replaced by synthetic alternatives in most applications. Rubber-based materials have to withstand extremely high shear forces and temperature fluctuations such as in aircraft and truck tires. There are also about 40,000 other items we use in everyday life, including about 400 products in medicine that rely on the use of natural rubber. Taraxacum koksaghyz, which was originally derived from Kazakhstan, produced natural rubber in laticifers of its taproot that accounts for around 15-40% of dry matter. Our research aims at the dissection and characterisation of rubber biosynthesis and to develop strategies for plant/crop improvement by molecular precision breeding.
Squalene and Triterpenes
Production of squalene and subsequently triterpenes in plants and yeast can build a solid platform for generating new bioreactive compounds for pharmaceutical (e.g. anti-tumor, anti-inflammation) or agronomic (e.g. insecticide) applications. Thus, we developed strategies to accumulate squalene and squalene-derivatives in plants by genetic engineering of the isoprenoid pathways and subsequent reactions in plants. Moreover, hemibiosynthetic approaches to produce these substances in yeast are a further goal of our research activities.