Poli Davide, Fabbri Elena, Goffredo Stefano, Airi Valentina, Franzellitti Silvia
Department of Biological, Geological and Environmental Sciences, University of Bologna, via S. Alberto, Ravenna, Italy.
Interdepartment Centre for Environmental Sciences Research, University of Bologna, via S. Alberto, Ravenna, Italy.
PLoS One. 2017 Feb 15;12(2):e0171456. doi: 10.1371/journal.pone.0171456. eCollection 2017.
This study investigates for the first time the transcriptional regulation of a stress-inducible 70-kDa heat shock protein (hsp70) in the scleractinian coral Pocillopora verrucosa sampled at three locations and two depths (3 m and 12 m) in Bangka Island waters (North Sulawesi, Indonesia). Percentage of coral cover indicated reduced habitat suitability with depth and at the Tanjung Husi (TA) site, which also displayed relatively higher seawater temperatures. Expression of the P. verrucosa hsp70 transcript evaluated under field conditions followed a depth-related profile, with relatively higher expression levels in 3-m collected nubbins compared to the 12-m ones. Expression levels of metabolism-related transcripts ATP synthase and NADH dehydrogenase indicated metabolic activation of nubbins to cope with habitat conditions of the TA site at 3 m. After a 14-day acclimatization to common and fixed temperature conditions in the laboratory, corals were subjected for 7 days to an altered thermal regime, where temperature was elevated at 31°C during the light phase and returned to 28°C during the dark phase. Nubbins collected at 12 m were relatively more sensitive to thermal stress, as they significantly over-expressed the selected transcripts. Corals collected at 3 m appeared more resilient, as they showed unaffected mRNA expressions. The results indicated that local habitat conditions may influence transcription of stress-related genes in P. verrucosa. Corals exhibiting higher basal hsp70 levels may display enhanced tolerance towards environmental stressors.
本研究首次调查了在印度尼西亚北苏拉威西邦加岛海域三个地点及两个深度（3米和12米）采集的鹿角杯形珊瑚（Pocillopora verrucosa）中应激诱导型70 kDa热休克蛋白（hsp70）的转录调控。珊瑚覆盖率百分比表明，随着深度增加以及在丹戎胡西（TA）站点，栖息地适宜性降低，该站点海水温度也相对较高。在野外条件下评估的鹿角杯形珊瑚hsp70转录本的表达呈现出与深度相关的特征，与在12米处采集的珊瑚断枝相比，在3米处采集的珊瑚断枝中表达水平相对较高。与代谢相关的转录本ATP合酶和NADH脱氢酶的表达水平表明，珊瑚断枝发生代谢激活以应对TA站点3米深处的栖息地条件。在实验室中对常见且固定的温度条件进行14天的驯化后，珊瑚在改变的热环境中处理7天，即光照阶段温度升至31°C，黑暗阶段温度恢复至28°C。在12米处采集的珊瑚断枝对热应激相对更敏感，因为它们显著过度表达了所选转录本。在3米处采集的珊瑚似乎更具恢复力，因为它们的mRNA表达未受影响。结果表明，当地栖息地条件可能会影响鹿角杯形珊瑚中应激相关基因的转录。表现出较高基础hsp70水平的珊瑚可能对环境应激源具有更强的耐受性。
