TY - JOUR
T1 - Nitric oxide mediates oxylipin production and grazing defense in diatoms
AU - Johnson, Matthew D.
AU - Edwards, Bethanie R.
AU - Beaudoin, David J.
AU - Van Mooy, Benjamin A. S.
AU - Vardi, Assaf
N1 - Acknowledgements - This research was funded by the Gordon and Betty Moore Foundation through Grant GBMF3301 to M.D.J., B.A.S.V.M. and A.V. We would also like to thank James R. Collins for his contributions to the lipidomic analyses, and Diane Stoecker, Miguel Frada, and Helen Fredericks for helpful discussions and assistance during the early stages of this project.
PY - 2020/2
Y1 - 2020/2
N2 - Diatom blooms are important features of productive marine ecosystems and are known to support higher trophic levels. However, when stressed or wounded, diatoms can produce oxylipin molecules known to inhibit the reproduction and development of copepods and decrease microzooplankton growth rates. Using oxylipin chemical treatments, lipidomic analysis and functional genomic approaches, we provide evidence that nitric oxide (NO) and oxylipin signalling pathways in diatoms respond to protist grazers, resulting in increased defence fitness and survival. Exposure of the diatom Phaeodactylum tricornutum to the dinoflagellate Oxyrrhis marina resulted in NO production by P. tricornutum and pronounced change in its dissolved oxylipin profile. Experimentally elevating levels of NO also resulted in increased oxylipin production, and lower overall grazing rates. Furthermore, O. marina preferentially grazed on P. tricornutum prey with lower levels of NO, suggesting that this molecule and its effect on oxylipin pathways play a key role in prey selection. Exposure of O. marina grazing on P. tricornutum to exogenous oxylipins also decreased grazing rates, which is consistent with a grazing deterrence role for these molecules. These results suggest that NO and oxylipin production help to structure diatom communities, in part by modulating interactions with microzooplankton predators.
AB - Diatom blooms are important features of productive marine ecosystems and are known to support higher trophic levels. However, when stressed or wounded, diatoms can produce oxylipin molecules known to inhibit the reproduction and development of copepods and decrease microzooplankton growth rates. Using oxylipin chemical treatments, lipidomic analysis and functional genomic approaches, we provide evidence that nitric oxide (NO) and oxylipin signalling pathways in diatoms respond to protist grazers, resulting in increased defence fitness and survival. Exposure of the diatom Phaeodactylum tricornutum to the dinoflagellate Oxyrrhis marina resulted in NO production by P. tricornutum and pronounced change in its dissolved oxylipin profile. Experimentally elevating levels of NO also resulted in increased oxylipin production, and lower overall grazing rates. Furthermore, O. marina preferentially grazed on P. tricornutum prey with lower levels of NO, suggesting that this molecule and its effect on oxylipin pathways play a key role in prey selection. Exposure of O. marina grazing on P. tricornutum to exogenous oxylipins also decreased grazing rates, which is consistent with a grazing deterrence role for these molecules. These results suggest that NO and oxylipin production help to structure diatom communities, in part by modulating interactions with microzooplankton predators.
UR - http://www.scopus.com/inward/record.url?scp=85076818187&partnerID=8YFLogxK
U2 - https://doi.org/10.1111/1462-2920.14879
DO - https://doi.org/10.1111/1462-2920.14879
M3 - مقالة
SN - 1462-2912
VL - 22
SP - 629
EP - 645
JO - Environmental Microbiology
JF - Environmental Microbiology
IS - 2
ER -