The digital plant: towards understanding Biocomplexity

The localization of PIN proteins in the root tip does not intuitively clarify why auxin would accumulate in the stem cell area. To understand the significance of polar auxin transport in auxin localization patterns, we analyze, in collaboration with the Theoretical Biology Group, computational models of root development. These have explained to us how a multicellular auxin flux loop made up by the PIN proteins is sufficient to maintain the auxin maximum and an auxin gradient across the meristem zone. The auxin gradient fits nicely with the PLETHORA gradients and these auxin-inducible root factors are likely to serve as the output of the auxin gradient to control cell division and cell expansion (Grieneisen et al. 2007, Nature 449: 1008-1013).


A computational Framework for auxin transport in the root

Our modeling framework is useful for the study of multiple other problems. We can include regulatory networks consisting of transcription factors and signaling proteins and we can analyze growth and cell division control. The use of computational modeling in close association with experiments is going to be an increasingly more important part of all of the work in our group; to underscore the importance of this aspect we have erected the Biocomplexity and Bioinformatics Institute, where we can foster collaboration between theoretical and experimental biologists working jointly on good model systems. 

Polarized PIN activity is sufficient for auxin maximum (white) and gradient