Friml Group

Plants and animals live different lives. Whereas animals typically react with a behavioral response, plants have acquired a highly adaptive development that tailors their phenotype to the environment. Plant development is therefore characterized by a remarkable adaptability to different environmental conditions. In terms of development, plants can do much more than animals: They initiate and grow new organs even during their post-embryonic development; they have permanent populations of stem cells throughout their whole life-span and they are able to change their direction of growth depending on external stimuli.

Many of these unique developmental events are mediated by the plant hormone auxin. Auxin is unique among plant signaling molecules. Unlike others, it is transported in a polar fashion through plant tissues and forms concentration gradients that can integrate endogenous signals as well as signals from the environment. Auxin transport is driven by the action of transport proteins, including efflux carriers of the PIN protein family. The localization of PIN transporters within cells determines the direction of auxin flow and thus represents a mechanism which can also define asymmetric auxin distribution within tissues. The auxin transport system thus provides positional and directional information for many aspects of adaptive plant development.

Our research has strongly interdisciplinary character. We conduct physiological, developmental biological and cell biological studies combining approaches of molecular biology, molecular genetics, biochemistry and mathematical modeling. The main areas of our research encompass:

1. Polar auxin transport
2. Cell polarity and polar targeting
3. Endocytosis and recycling
4. Non-transcriptional mechanisms of signaling

In the course of our studies we obtained fundamental insights into mechanisms governing plant development. They also show how signals from the environment are integrated into endogenous signaling networks and translated into changes in plant growth and development. Many of our discoveries are relevant for agricultural applications. Our results provide a conceptual possibility to manipulate developmental processes including plant architecture and fruit set and ripening. Manipulating root growth and branching can generate root systems that are more suitable for arid and low nutrition soils.