Transcriptional Response to Seawater Acidification and Hyperthermal Stress in the Azooxanthellate Octocoral, Scleronephthya Gracillimum

Abstract

The soft coral Scleronephthya gracillimum, is an azooxanthellate octocoral order Alcyonacea. The local and global environmental stresses on its habitat have led to this coral being observational species. To study the stress responses to the increased seawater temperature and marine acidification, the transcriptional changes in S. gracillimum exposed to hyperthermal and acidification condition were investigated using microarray. Transcriptome analysis preceded to identify the unigenes with functional annotation and S. gracillimum microarray was constructed with 33,298 contigs. The differentially expressed genes were classified with the gene ontology term enrichment analysisfrom the coral groups stressed by high temperatures, acidification conditions and concurrent temperature and acidification conditions, respectively. The combined effect of hyperthermal and acidification stresses on transcriptional level in S. gracillimum was described with mortality and morphological changes in 24hr post-exposure.