The University of Southampton
University of Southampton Institutional Repository

Optical feedback loop involving dinoflagellate symbiont and scleractinian host drives colourful coral bleaching

Optical feedback loop involving dinoflagellate symbiont and scleractinian host drives colourful coral bleaching
Optical feedback loop involving dinoflagellate symbiont and scleractinian host drives colourful coral bleaching
Coral bleaching, caused by the loss of brownish-coloured dinoflagellate photosymbionts from the host tissue of reef-building corals, is a major threat to reef survival. Occasionally, bleached corals become exceptionally colourful rather than white. These colours derive from photoprotective green fluorescent protein (GFP)-like pigments produced by the coral host. There is currently no consensus regarding what causes colourful bleaching events and what the consequences for the corals are. Here, we document that colourful bleaching events are a recurring phenomenon in reef regions around the globe. Our analysis of temperature conditions associated with colourful bleaching events suggests that corals develop extreme colouration within 2-3 weeks after exposure to mild or temporary heat stress. We demonstrate that the increase of light fluxes in symbiont-depleted tissue promoted by reflection of the incident from the coral skeleton induces strong expression of the photoprotective coral host pigments. We describe an optical feedback loop involving both partners of the association, discussing that the mitigation of light stress offered by host pigments could facilitate recolonization of bleached tissue by symbionts. Our data indicate that colourful bleaching has the potential to identify local environmental factors, such as nutrient stress, that can exacerbate the impact of elevated temperatures on corals, to indicate the severity of heat stress experienced by corals and to gauge their post- stress recovery potential.
color, coral bleaching, feedback loop, green fluorescent protein (GFP), nutrient stress, optics, photoprotection, pigments, recovery, symbiosis
0960-9822
2433-2445.e3
Bollati, Elena
5d9ec6e5-83e3-41b3-91ce-aa112949cd1f
D'Angelo, Cecilia
0d35b03b-684d-43aa-a57a-87212ab07ee1
Alderdice, Rachel
7515e44b-774f-477c-ac10-ae7efcfbd1e2
Pratchett, Morgan
b2ef3783-9b65-434f-8133-bf2fef94036d
Ziegler, Maren
dd7fe6be-ed96-4d50-812d-d576f37e9f4c
Wiedenmann, Joerg
ad445af2-680f-4927-90b3-589ac9d538f7
Bollati, Elena
5d9ec6e5-83e3-41b3-91ce-aa112949cd1f
D'Angelo, Cecilia
0d35b03b-684d-43aa-a57a-87212ab07ee1
Alderdice, Rachel
7515e44b-774f-477c-ac10-ae7efcfbd1e2
Pratchett, Morgan
b2ef3783-9b65-434f-8133-bf2fef94036d
Ziegler, Maren
dd7fe6be-ed96-4d50-812d-d576f37e9f4c
Wiedenmann, Joerg
ad445af2-680f-4927-90b3-589ac9d538f7

Bollati, Elena, D'Angelo, Cecilia, Alderdice, Rachel, Pratchett, Morgan, Ziegler, Maren and Wiedenmann, Joerg (2020) Optical feedback loop involving dinoflagellate symbiont and scleractinian host drives colourful coral bleaching. Current Biology, 30 (13), 2433-2445.e3. (doi:10.1016/j.cub.2020.04.055).

Record type: Article

Abstract

Coral bleaching, caused by the loss of brownish-coloured dinoflagellate photosymbionts from the host tissue of reef-building corals, is a major threat to reef survival. Occasionally, bleached corals become exceptionally colourful rather than white. These colours derive from photoprotective green fluorescent protein (GFP)-like pigments produced by the coral host. There is currently no consensus regarding what causes colourful bleaching events and what the consequences for the corals are. Here, we document that colourful bleaching events are a recurring phenomenon in reef regions around the globe. Our analysis of temperature conditions associated with colourful bleaching events suggests that corals develop extreme colouration within 2-3 weeks after exposure to mild or temporary heat stress. We demonstrate that the increase of light fluxes in symbiont-depleted tissue promoted by reflection of the incident from the coral skeleton induces strong expression of the photoprotective coral host pigments. We describe an optical feedback loop involving both partners of the association, discussing that the mitigation of light stress offered by host pigments could facilitate recolonization of bleached tissue by symbionts. Our data indicate that colourful bleaching has the potential to identify local environmental factors, such as nutrient stress, that can exacerbate the impact of elevated temperatures on corals, to indicate the severity of heat stress experienced by corals and to gauge their post- stress recovery potential.

Text
CURRENT_BIOLOGY_D_19_01555_R1_for_approval - Accepted Manuscript
Download (4kB)
Text
1-s2.0-S0960982220305716-main - Proof
Download (4kB)

More information

Accepted/In Press date: 21 April 2020
e-pub ahead of print date: 21 May 2020
Keywords: color, coral bleaching, feedback loop, green fluorescent protein (GFP), nutrient stress, optics, photoprotection, pigments, recovery, symbiosis

Identifiers

Local EPrints ID: 438830
URI: http://eprints.soton.ac.uk/id/eprint/438830
ISSN: 0960-9822
PURE UUID: 90b528be-fd74-4022-913e-04f75e42899d
ORCID for Elena Bollati: ORCID iD orcid.org/0000-0003-3536-4587
ORCID for Joerg Wiedenmann: ORCID iD orcid.org/0000-0003-2128-2943

Catalogue record

Date deposited: 25 Mar 2020 17:31
Last modified: 15 Sep 2021 05:12

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×