Genome-wide transcriptomic responses of the seagrasses Zostera marina and Nanozostera noltii under a simulated heatwave confirm functional types.
Genome-wide transcription analysis between related species occurring in overlapping ranges can provide insights into the molecular basis underlying different ecological niches. The co-occurring seagrass species, Zostera marina and Nanozostera noltii, are found in marine coastal environments throughout the northern hemisphere. Z. marina is often dominant in subtidal environments and subjected to fewer temperature extremes compared to the predominately intertidal and more stress-tolerant N. noltii. We exposed plants of both species to a realistic heat wave scenario in a common-stress-garden experiment. Using RNA-seq (~7million reads/library), four Z. marina and four N. noltii libraries were compared representing northern (Denmark) and southern (Italy) locations within the co-occurring range of the species' European distribution. A total of 8977 expressed genes were identified, of which 78 were directly related to heat stress. As predicted, both species were negatively affected by the heat wave, but showed markedly different molecular responses. In Z. marina the heat response was similar across locations in response to the heatwave at 26°C, with a complex response in functions related to protein folding, synthesis of ribosomal chloroplast proteins, proteins involved in cell wall modification and heat shock proteins (HSPs). In N. noltii the heat response markedly differed between locations, while HSP genes were not induced in either population. Our results suggest that as coastal seawater temperatures increase, Z. marina will disappear along its southern most ranges, whereas N. noltii will continue to move north. As a consequence, sub- and intertidal habitat partitioning may weaken in more northern regions because the higher thermal tolerance of N. noltii provides a competitive advantage in both habitats. Although previous studies have focused on HSPs, the present study clearly demonstrates that a broader examination of stress related genes is necessary.
Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, 48149 Münster, Germany. Electronic address: susanne.franssen@vetmeduni.ac.at.
Susanne U
SU
Franssen
Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, 48149 Münster, Germany.
Jenny
J
Gu
Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, 48149 Münster, Germany.
Gidon
G
Winters
Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, 48149 Münster, Germany.
Ann-Kathrin
AK
Huylmans
Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, 48149 Münster, Germany.
Isabell
I
Wienpahl
Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, 48149 Münster, Germany.
Maximiliane
M
Sparwel
Marine Benthic Ecology and Evolution Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
James A
JA
Coyer
Marine Benthic Ecology and Evolution Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
Jeanine L
JL
Olsen
GEOMAR Helmholtz-Centre for Ocean Research Kiel, Evolutionary Ecology of Marine Fishes, Düsternbrooker Weg 20, 24105 Kiel, Germany.
Thorsten B H
TB
Reusch
Institute for Evolution and Biodiversity, University of Münster, Hüfferstr. 1, 48149 Münster, Germany.
Erich
E
Bornberg-Bauer
D001483:Base Sequence; D003718:Denmark; D020869:Gene Expression Profiling; D018745:Genome, Plant / Q000235:genetics*; D006358:Hot Temperature; D007558:Italy; D008969:Molecular Sequence Data; D017423:Sequence Analysis, RNA; D013045:Species Specificity; D013312:Stress, Physiological / Q000235:genetics*; D059467:Transcriptome / Q000235:genetics*; D035962:Zosteraceae / Q000235:genetics* / Q000378:metabolism*
Global warming; Heatwave; Inter-species transcriptomics; Intra-specific variability; RNA-seq; Zostera marina &Nanozostera noltii