Transcriptional response of the heat shock gene hsp70 aligns with differences in stress susceptibility of shallow-water corals from the Mediterranean Sea. (September 2018)

• Record Type: Journal Article
• Authors: Franzellitti, Silvia; Airi, Valentina; Calbucci, Diana; Caroselli, Erik; Prada, Fiorella; Voolstra, Christian R.; Mass, Tali; Falini, Giuseppe; Fabbri, Elena; Goffredo, Stefano
• Is Part Of: Marine environmental research. Volume 140(2018)
• Page Start: 444
• Page End: 454
• Publication Date: 2018-09
• Subjects: Thermal stress -- Coral -- Gene expression -- Heat shock protein -- Physiological plasticity -- Climate change; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2018.07.006
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: Shallow-water corals of the Mediterranean Sea are facing a dramatic increase in water temperature due to climate change, predicted to increase the frequency of bleaching and mass mortality events. However, supposedly not all corals are affected equally, as they show differences in stress susceptibility, as suggested by physiological outputs of corals along temperature gradients and under controlled conditions in terms of reproduction, demography, growth, calcification, and photosynthetic efficiency. In this study, gene expression and induction of a 70-kDa heat shock protein (HSP70) was analyzed in five common shallow-water hard corals in the Mediterranean Sea, namely Astroides calycularis, Balanophyllia europaea, Caryophyllia inornata, Cladocora caespitosa, and Leptopsammia pruvoti. The main aim was to assess the contribution of this evolutionary conserved cytoprotective mechanism to the physiological plasticity of these species that possess different growth modes (solitary vs colonial) and trophic strategies (zooxanthellate vs azooxanthellate). Using quantitative real-time PCR, in situ hsp70 baseline levels and expression profiles after a heat-shock exposure were assessed. Levels of hsp70 and heat stress induction were higher in zooxanthellate than in azooxanthellate species, and different heat stress transcriptional profiles were observed between colonial and solitary zooxanthellate corals. On the whole, the hsp70 transcriptional response to heat stress aligns with stress susceptibility of the species and suggests a contribution of trophic strategy and morphology in shaping coral resilience to stress. Understanding these molecular processes may contribute to assess the potential effects and relative resilience of Mediterranean corals under climate change. Graphical abstract: Highlights: In situ hsp70 baseline levels and heat shock induction was analyzed in 5 shallow-water hard corals in the Mediterranean Sea. The species have different growth modes (solitary vs colonial) and trophic strategies (zooxanthellate vs azooxanthellate). In situ hsp70 baseline expression was higher in zooxanthellate than in azooxanthellate species. Different heat stress transcriptional profiles were observed between colonial and solitary zooxanthellate corals. On the whole, the hsp70 response to heat stress aligns with peculiar stress susceptibility of the species.