Millimetre-resolution mapping of citrate exuded from soil-grown roots using a novel, low-invasive sampling technique

Abstract The reliable sampling of root exudates in soil-grown plants is experimentally challenging. This study aimed at developing a citrate and mapping technique with millimetre-resolution using DGT (diffusive gradients thin films) ZrOH-binding gels. Citrate adsorption kinetics, capacity, stability ZrOH gels were evaluated. applied to generate 2D maps exuded by white lupin roots grown rhizotron phosphorus-deficient soil. was adsorbed quantitatively rapidly the gels; these can be stored after for several weeks prior analysis. capacity gel depends on ionic strength pH soil solution, but suitable sampling. We generated first time rhizotron-grown millimetre resolution measure an illustrated plant response phosphorus fertilization, demonstrating that DGT-based studying exudation environments, high spatial resolution. change binding material would also allow other exudate classes profiles entire systems. These aspects are crucial cultivar breeding selection.