Summary The transport of water into leaves and the export of sugar out of leaves is crucial for a plant's life. Two vascular systems are responsible for these processes and are finely regulated by water availability, transpiration and photosynthesis. The aim of our interdisciplinary project is to assess water usage and understand the checkpoints for balancing water and sugar transport. With the funded gas exchange system we can measure photosynthesis rates, humidity, and respiration and challenge leaves with different light intensities, CO2 levels and temperatures. For this, the system will be connected to a leaf chamber allowing for the first time to visualise water movement in intact leaves in a µCT X-ray scanner and later in a synchrotron beamline for higher spatial and temporal resolution.