Transcriptional responses in Ecklonia cava to short-term exposure to hyperthermal stress

Abstract

Rapid climate change accelerates the damage to many valuable marine ecosystems, including macroalgal forests and coral reefs. To understand the biological responses of kelp species to increased seawater temperatures, we isolated the genes that responded to hyperthermal stress conditions in Ecklonia cava. Thalli of E. cava were exposed to seawater at 20 or 24°C, and the genes whose transcript levels changed in response to hyperthermal stress were identified with microarray hybridization. Eighty-nine candidate genes were identified, 49 of which were upregulated and 40 were downregulated by hyperthermal stress. Gene Ontology mapping showed that cellular oxidant detoxification, the regulation of cellular metabolic processes, and photosynthesis processes were affected by increased ocean temperatures. The functions of some isolated genes were also analyzed to predict the possible changes in the metabolism of E. cava under hyperthermal stress. The differentially expressed genes isolated here may serve as molecular biomarkers, allowing us to better understand the biological responses of marine organisms to environmental changes.