Accelerated Nitrogen Cycling on Seagrass Leaves in a High-CO2 World

Abstract

Seagrass meadows form highly productive and diverse ecosystems in coastal areas worldwide, where they are increasingly exposed to ocean acidification (OA). Efficient nitrogen (N) cycling and uptake are essential to maintain plant productivity, but the effects of OA on N transformations in these systems are poorly understood. Here we show that complete N cycling occurs on leaves of the Mediterranean seagrass Posidonia oceanica, with OA affecting both N gain and loss while the prokaryotic community structure remains largely unaffected. Daily leaf-associated \(N_2\) fixation contributed to 35% of the plant’s N demand under ambient pH, whereas it contributed to 45% under OA. Nitrification potential was only detected under OA, and N-loss via \(N_2\) production increased, although the balance remained decisively in favor of enhanced N gain. Our work highlights the role of the N-cycling microbiome in seagrass adaptation to OA, with key N transformations accelerating towards increased N gain

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Citation

BibTeX citation:

@online{j2023,
  author = {J, Berlinghof and LM, Montilla and F, Peiffer and GM, Quero
    and U, Marzocchi and TB, Meador and F, Margiotta and M, Abagnale and
    C, Wild and C, Cardini},
  title = {Accelerated {Nitrogen} {Cycling} on {Seagrass} {Leaves} in a
    {High-CO2} {World}},
  date = {2023-05-22},
  url = {https://www.luismmontilla.com/papers/berlinghof2023/},
  doi = {10.1101/2023.05.19.541481v1},
  langid = {en},
  abstract = {Seagrass meadows form highly productive and diverse
    ecosystems in coastal areas worldwide, where they are increasingly
    exposed to ocean acidification (OA). Efficient nitrogen (N) cycling
    and uptake are essential to maintain plant productivity, but the
    effects of OA on N transformations in these systems are poorly
    understood. Here we show that complete N cycling occurs on leaves of
    the Mediterranean seagrass \_Posidonia oceanica\_, with OA affecting
    both N gain and loss while the prokaryotic community structure
    remains largely unaffected. Daily leaf-associated \$N\_2\$ fixation
    contributed to 35\% of the plant’s N demand under ambient pH,
    whereas it contributed to 45\% under OA. Nitrification potential was
    only detected under OA, and N-loss via \$N\_2\$ production
    increased, although the balance remained decisively in favor of
    enhanced N gain. Our work highlights the role of the N-cycling
    microbiome in seagrass adaptation to OA, with key N transformations
    accelerating towards increased N gain}
}

For attribution, please cite this work as:

J, Berlinghof, Montilla LM, Peiffer F, et al. 2023. “Accelerated Nitrogen Cycling on Seagrass Leaves in a High-CO2 World.” bioRxiv, May 22. https://doi.org/10.1101/2023.05.19.541481v1.