Utricularia is a genus with highly interesting ecophysiology. The characteristic trapping organs are small hollow utricles filled with fluid that are heavily colonized by microorganisms. Completely sealed from the outside environment, except for firing events, the lumen of a trap contains fully functional and complex microbial loop adapted to the current, but permanently changing conditions in the environment, including changing nutrient supply.
The Utricularia genus exhibits anomalous molecular evolutionary features, such as highly increased rates of nucleotide substitution and dynamic evolution of genome size, which ranges between 60-1500 megabases (smallest plant genomes found to date), depending on the species or even population. The small genome size makes these plants great model species and it is argued that they are prime candidates for further research on the complexities of plant ecophysiology associated with carnivory, metagenomic surveys of novel plant nutrient utilization pathways, whole-plant and trap comparative development, as well as the evolution of the minimal angiosperm genome.
The nature of the plant–microbe interaction between Utricularia is virtually unknown, although it is suspected to play a key role in plant nutrient acquisition. We expect to identify, as specifically as possible, the microbe-dependent metabolic pathways in Utricularia and hence make conclusions about the ecological benefits, which apparently cost the plant significant amounts of primary production. We hope to put these results together with the ongoing work on the functional capabilities of trap microorganisms and set them into a broader ecological, perhaps even evolutionary perspective.
As our main model species, we have selected Utricularia vulgaris L., which we consider to be representative of aquatic Utricularia species that has often been used in previous ecophysiological studies.