The ecology of bladderworts: the unique hunting-gathering-farming strategy in plants

Carnivorous plants typify a mixotrophic strategy where autotrophy is supported by predation on animals, achieved through fascinating morpho-physiological adaptations and unique mutualisms. Exploring such symbiotic interactions is pivotal to understand how carnivorous plants feed upon wide ranges of resources, by relying on symbiont-mediated digestion. This concept finds its extreme realization in Utricularia (bladderwort), the largest genus of carnivorous plants, where the formation of a symbiotic microbiota within the traps drives its trophic resources further, including algae and complex organic matter. The present review synthesizes the key aspects of Utricularia ecology, from evolution to habitat selection, looking into the fascinating complexity of the structure and the microbiome of their traps. It highlights the gaps and guts in the understanding of bladderworts, including promising applications based on models of the Utricularia-microbiome system and the possible development of biomimetic devices. From the environmental drivers through the solutions developed by these plants, the review offers a comprehensive view of their unique ecology, which could be factually defined a “mixotrophic omnivory”.