Expression analyses of stress-responsive genes in the hermatypic coral and its symbiotic dinoflagellates after exposure to the herbicide Diuron.

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Diuron is one of the most frequently applied herbicides in sugarcane farming in southern Japan, and Australia. In addition, it is used as a booster substance in copper-based antifouling paints. Due to these various uses, Diuron is released into the marine environment; however, little information is available on gene expression in corals and their symbiotic algae exposed to Diuron. We investigated the effects of Diuron on stress-responsive gene expression in the hermatypic coral and its symbiotic dinoflagellates. After seven days of exposure to 1 µg/L and 10 µg/L Diuron, no significant changes in the body colour of corals were observed. However, quantitative reverse transcription-polymerase chain reaction analyses revealed that the expression levels of stress-responsive genes, such as heat shock protein 90 (), , and calreticulin (), were significantly downregulated in corals exposed to 10 µg/L of Diuron for seven days. Moreover, aquaglyceroporin was significantly downregulated in corals exposed to environmentally relevant concentrations of 1 µg/L Diuron. In contrast, no such effects were observed on the expression levels of other stress-responsive genes, such as oxidative stress-responsive proteins, methionine adenosyltransferase, and green/red fluorescent proteins. Diuron exposure had no significant effect on the expression levels of , , or in the symbiotic dinoflagellates. These results suggest that stress-responsive genes, such as s, respond differently to Diuron in corals and their symbiotic dinoflagellates and that s and s may be useful molecular biomarkers for predicting stress responses induced by the herbicide Diuron.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s42995-023-00183-0.