Publication Date:
2022-05-25
Description:
© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Chemosphere 186 (2017): 527-534, doi:10.1016/j.chemosphere.2017.08.024.
Description:
The effects of an allelochemical extracted from the culture filtrate of diatom Phaeodactylum
tricornutum on the raphidophyte Heterosigma akashiwo were investigated using a series of
morphological, physiological and biochemical characters. Growth experiments showed that H.
akashiwo was significantly inhibited immediately after exposure to the allelochemical, with many cells
rapidly dying and lysing based on microscopic observation. The effects of the allelochemical on the
surviving cells were explored using Scanning Electron Microscopy (SEM) and Flow cytometry (FCM),
the latter by examination of a suite of physiological parameters (membrane integrity, esterase activity,
chlorophyll-a content, membrane potential). The results demonstrate that the membrane of H. akashiwo
was attacked by the allelochemical directly, causing cell membrane breakage and loss of integrity.
Esterase activity was the most sensitive indicator of the impacts of the allelochemical. Membrane potential and chlorophyll-a content both showed significant decreases following exposure of the
Heterosigma cells to high concentrations of the allelochemical for 5 and 6 days. Both were affected,
but the membrane potential response was more gradual compared to other effects. The cell size of H.
akashiwo did not change compared with the control group. The surviving cells were able to continue to
grow and in a few days, re-establish a successful culture, even in the presence of residual
allelochemical, suggesting either development of cellular resistance, or the degradation of the chemical.
Description:
The authors wish to thank the National Programme on Global Change and Air-Sea Interaction (Grant
No. GASI-03-01-02-01); the National Key Research and Development Program [Grant No.
2016YFC1402101]; the assessment of nanomaterials on biological and ecological effects in the coastal
area (Grant No. 201505034).
Keywords:
Allelochemical
;
Phaeodactylum tricornutum
;
Heterosigma akashiwo
;
Flow cytometry
;
Physiological characters
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
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