Open AccessMicroorganisms facilitate uptake of dissolved organic nitrogen by seagrass leaves
Author(s) -
Flavia Tarquinio,
Jeremy Bourgoure,
Annette Koenders,
Bonnie Laverock,
Christin Säwström,
Glenn A. Hyndes
Publication year - 2018
Publication title -
the isme journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.422
H-Index - 173
eISSN - 1751-7370
pISSN - 1751-7362
DOI - 10.1038/s41396-018-0218-6
Subject(s) - seagrass , microorganism , biology , nitrogen , environmental chemistry , botany , ecosystem , nitrogen cycle , δ15n , stable isotope ratio , ecology , bacteria , chemistry , δ13c , genetics , organic chemistry , physics , quantum mechanics
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 15 N-amino acids (aa), with and without associated microorganisms. Samples were collected after 0.5, 2, 6 and 12 h. Both bulk stable isotope and nanoscale secondary ion mass spectrometry (NanoSIMS) analysis showed high accumulation of 15 N within seagrass leaf tissues with an associated microbiota, but not in plants devoid of microorganisms. These results significantly change our understanding of the mechanisms of seagrass nitrogen use and provide evidence that seagrass microbiota increase nitrogen availability for uptake by seagrass leaves by mineralising aa, thus enhancing growth and productivity of these important coastal ecosystems.