Exposure to the Florida red tide dinoflagellate, Karenia brevis, and its associated brevetoxins induces ecophysiological and proteomic alterations in Porites astreoides

• Published in: PloS one Vol. 15; no. 2; p. e0228414
• Main Authors: Reynolds, David A, Yoo, Mi-Jeong, Dixson, Danielle L, Ross, Cliff
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 07.02.2020; Public Library of Science (PLoS)
• Subjects: Animal behavior; Animals; Biology; Biology and Life Sciences; Brevetoxins; Cellular stress response; Chemical analysis; Chemical treatment; Coral reefs; Corals; Dinoflagellates; Dinoflagellida - pathogenicity; Earth Sciences; Ecological effects; Ecology; Ecology and Environmental Sciences; Ecosystem; Energy metabolism; Environmental Exposure - adverse effects; Exposure; Fluorimetry; Fluorometry; Gene expression; Genomes; Harmful Algal Bloom - drug effects; Harmful Algal Bloom - physiology; Homeostasis; Karenia brevis; Larva - drug effects; Larva - growth & development; Larva - metabolism; Larvae; Marine toxins; Marine Toxins - toxicity; Metabolism; Microorganisms; Novels; Organic chemistry; Oxocins - toxicity; Oxygen; Peptides; Population studies; Porites astreoides; Protein folding; Protein turnover; Proteins; Proteome - analysis; Proteomics; Reactive oxygen species; Red tides; Research and Analysis Methods; Seawater; Tides; Time; Time dependence; Water analysis; Water pollution effects; Water quality; Florida Keys; Florida; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0228414

As reef-building corals are increasingly being exposed to persistent threats that operate on both regional and global scales, there is a pressing need to better understand the complex processes that diminish coral populations. This study investigated the impacts of the Florida red tide dinoflagellate Karenia brevis and associated brevetoxins on selected facets of coral biology using Porites astreoides as a model system. When provided with choice assays, P. astreoides larvae were shown to actively avoid seawater containing red tide (5×105 cells L-1-7.6×106 cells L-1) or purified brevetoxins (0.018 μg mL-1 brevetoxin-2 and 0.0018 μg mL-1 brevetoxin-3). However, forced exposure to similar treatments induced time-dependent physiological and behavioral changes that were captured by PAM fluorometry and settlement and survival assays, respectively. Adult fragments of P. astreoides exposed to red tide or associated brevetoxins displayed signs of proteomic alterations that were characterized by the use of an iTRAQ-based quantitative proteomic analysis. The novel use of this technique with P. astreoides demonstrated that protein regulation was highly contingent upon biological versus chemical treatment (i.e. live K. brevis vs. solely brevetoxin exposure) and that several broad pathways associated with cell stress were affected including redox homeostasis, protein folding, energy metabolism and reactive oxygen species production. The results herein provide new insight into the ecology, behavior and sublethal stress of reef-building corals in response to K. brevis exposure and underscore the importance of recognizing the potential of red tide to act as a regional stressor to these important foundation species.