The majority of available data on phytohormone profiles and metabolism concerns vascular plants. Žižková et al. monitor the mechanisms by which two main groups of phytohormones, cytokinins and auxins, control homeostasis in cyanobacteria and algae, aquatic communities which exhibit a different metabolic modus operandi to vascular plants.

An analysis of cytokinin oxidase/dehydrogenase activity, tRNA-bound cytokinins, [3H]trans-zeatin and [3H]indole-3-acetic acid metabolic activity and changes in cytokinin and auxin levels during Scenedesmus obliquus growth reveals that cytokinin and auxin drive the metabolic pathways which sustain cyanobacteria and algae.