Microorganisms facilitate uptake of dissolved organic nitrogen by seagrass leaves.

Microorganisms play a critical role in nitrogen cycling by mineralising dissolved organic nitrogen (DON) compounds into bioavailable inorganic forms (DIN). Although DIN is crucial for seagrass growth, the hypothesis that seagrass leaf associated-microorganisms could convert DON to forms available for plant uptake has never been tested. We conducted a laboratory-based experiment in which seagrass (Posidonia sinuosa) leaves were incubated with N-amino acids (aa), with and without associated microorganisms.