Cytokinin and auxin biosynthesis and distribution patterns have been studied intensively in many terrestrial plant species. Until now, no direct phytohormonal screening has been carried out in rootless, aquatic, carnivorous plants.
Šimura et al. present here insight into cytokinin and auxin levels, their distribution and relative abundance in segmented shoots and turions of Aldrovanda vesiculosa and Utricularia australis, which exhibit very rapid apical growth with simultaneous senescence of basal parts of shoots. Although both species showed similar trends in basipetal decrease of active cytokinins and in the cytokinin-to-auxin ratio, our detailed metabolic analysis revealed interesting differences in the cytokinin regulation.