The cellular stress response of the scleractinian coral Goniopora columna during the progression of the black band disease

Abstract

Black band disease (BBD) is a widespread coral pathology caused by a microbial consortium dominated by cyanobacteria, which is significantly contributing to the loss of coral cover and diversity worldwide. Since the effects of the BBD pathogens on the physiology and cellular stress response of coral polyps appear almost unknown, the expression of some molecular biomarkers, such as Hsp70, Hsp60, HO-1, and MnSOD, was analyzed in the apparently healthy tissues of Goniopora columna located at different distances from the infection and during two disease development stages. All the biomarkers displayed different levels of expression between healthy and diseased colonies. In the healthy corals, low basal levels were found stable over time in different parts of the same colony. On the contrary, in the diseased colonies, a strong up-regulation of all the biomarkers was observed in all the tissues surrounding the infection, which suffered an oxidative stress probably generated by the alternation, at the progression front of the disease, of conditions of oxygen supersaturation and hypoxia/anoxia, and by the production of the cyanotoxin microcystin by the BBD cyanobacteria. Furthermore, in the infected colonies, the expression of all the biomarkers appeared significantly affected by the development stage of the disease. In conclusion, our approach may constitute a useful diagnostic tool, since the cellular stress response of corals is activated before the pathogens colonize the tissues, and expands the current knowledge of the mechanisms controlling the host responses to infection in corals.

Astrocoryne cabela, gen. nov. et sp. nov. (Hydrozoa : Sphaerocorynidae), a new sponge-associated hydrozoan

“…For instance, differences in hydranths might be related to salinity (e.g. Kinne 1957;Kinne and Paffenhöfer 1965), which differs by about five psu between the two sampling localities (Reimer et al 2017;Seveso et al 2017), and variations in the pedicel might be due to distinct reactions of the polyps to different hosts.…”

The Pathobiome in Animal and Plant Diseases

“…Photosynthetic algae, both bacterial and eukaryotic, can also infect a range of vertebrate hosts, causing dermatological and systemic pathologies. Examples of algal infections include Chlorochytrium in cichlid fish, Chlorella in sheep and other vertebrates [24,25], and cyanobacteria associated with black band disease of corals [26]. Cryptic infections include pathogens with dormant life stages that may asymptomatically infect a diversity of hosts or tissues, and be triggered to cause negative effects in response to environmental changes [9].…”

Transcriptome, expression, and activity analyses reveal a vital heat shock protein 70 in the stress response of stony coral Pocillopora damicornis

“…For example, the expression levels of HSP70 mRNA increased significantly in stony coral Acropora aspera and Montastraea franksi under the heat and copper stresses, respectively (Louis et al 2017;Venn et al 2009). The expression of HSP70 proteins were induced by pathogen infection in Goniopora columna and heat stress in Stylophora pistillata and Porites cylindrca (Seveso et al 2017;Fitt et al 2009). Furthermore, it has been considered that HSP70 has implications for the bleaching of stony coral under environmental stress (Douglas 2003;Downs et al 2002;Hayes and King 1995), and therefore, it has been incorporated in a molecular biomarker system to assess the physiological status of stony coral Montastraea faveolata challenged by heat stress (Downs et al 2000), or employed as an crucial parameter to estimate the tolerance of stony corals to environmental change (Nakamura et al 2012;Brown et al 2002).…”