Video of O2 and CO2 dynamics around a root of the fresh water plant; Lobelia dortmanna, during light and dark alternations. The 2D distribution of O2 and CO2 was recorded during a dark (12h)-light (12h)-dark (12h) interval using the Planar optode system; VisiSens TD from PreSens - Precision Sensing GmbH, Regensburg, Germany. The 2D distribution of O2 and CO2 was recorded as single images at 30min intervals. Subsequently, the images were compiled to a video. The video demonstrates strong daily variation in O2 and CO2 around Lobelia dortmanna root-tips controlled by O2 release and CO2 uptake by roots during illumination of the aboveground biomass.