The hormone cytokinin plays an important role in regulating plant growth and development. A raised or lowered level of the hormone functions to support the formation and growth of blossoms, acts as a rejuvenation cure to delay leaf aging, or stimulates root growth. Cytokinin was discovered in the 1950s but significant progress in understanding the hormone function was achieved only recently with the novel methods of molecular genetics. The research group led by Professor Thomas Schmülling uses Arabidopsis (Arabidopsis thaliana) as a model to investigate a variety of issues related to cytokinin metabolism and signal transfer. The findings from this basic research are now being transferred to crop plants, in particular oilseed rape and barley. One aim is, for example, to improve the root system by intervening with cytokinin activity, and thus optimise the absorption of water and minerals. In addition to enhancing plant resistance to drought, the research also sets out to improve seed yield in oilseed rape. Targeted control of the cytokinin balance not only changes the size of the reproductive meristem but also influences leaf aging, which plays a role in the nutrient export into the seeds and thus affects yield.