Short-Term Thermal Acclimation Modifies the Metabolic Condition of the Coral Holobiont
Short-Term Thermal Acclimation Modifies the Metabolic Condition of the Coral Holobiont
复制标题
短期热适应改变了珊瑚全生物的代谢状况
DOI：
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发表时间：
2018
影响因子：
3.7
通讯作者：
A. Meibom
中科院分区：
文献类型：
--
作者：
E. Gibbin;T. Krueger;H. Putnam;K. Barott;Julia Bodin;R. Gates;A. Meibom
珊瑚宿主和具有光合作用的甲藻之间的营养共生是珊瑚礁功能的基础。海水温度的上升破坏了这种关系的稳定，导致全球珊瑚覆盖率急剧下降。热史被认为在塑造珊瑚对随后的热应力的反应方面发挥了重要作用。在这里，我们将Pocillopora Damicoris暴露在两种热习服条件下(环境和温暖)，并比较驯化对随后的七天热应激事件的珊瑚全息生物的反应的影响。在整个热应激过程中，我们进行了全息水平(总光合作用、呼吸作用、寄主蛋白含量、共生体密度和叶绿素含量)的每日生理测量，并在热应激事件结束时使用NanoSIMS进行了13C-碳酸氢盐和15N-硝酸盐同化的细胞水平成像。热适应历史对热事件期间在全息水平上进行的测量的影响可以忽略不计。温驯化珊瑚和常温驯化珊瑚的O2-收支没有差异，只有寄主蛋白质、共生体密度和叶绿素含量的微小波动。相比之下，这种差异反应的缺乏并没有反映在细胞水平上。与环境驯化的珊瑚相比，温驯化的珊瑚在宿主胃真皮和脂体中的13C富集量显著增加，而在共生体和宿主组织层中的15N-硝酸盐同化显著降低。我们讨论了在温暖驯化的珊瑚中，在没有光合作用破坏的情况下，共生体碳酸氢盐和硝酸盐同化之间发生脱节的潜在原因。我们认为，这要么代表了氮素利用的转变，要么代表了宿主对供应的限制。我们的发现提出了几个关于氮代谢在热应激中所起作用的有趣假说，如果我们想要了解珊瑚全叶藻的适应能力，这些假说将值得进一步研究。
The nutritional symbiosis between coral hosts and photosynthetic dinoflagellates is fundamental to the functioning of coral reefs. Rising seawater temperatures destabilize this relationship, resulting in drastic declines in world-wide coral cover. Thermal history is thought to play an important role in shaping a coral’s response to subsequent thermal stress. Here, we exposed Pocillopora damicornis to two thermal acclimation regimes (ambient vs. warm) and compared the effect that acclimation had on the coral holobiont’s response to a subsequent seven day heat stress event. We conducted daily physiological measurements at the holobiont level (gross photosynthesis, respiration, host protein content, symbiont density and chlorophyll content) throughout the heat stress event, as well as cellular-level imaging of 13C-bicarbonate and 15N-nitrate assimilation using NanoSIMS, at the end of the heat stress event. Thermal acclimation history had a negligible effect on the measurements conducted at the holobiont level during the heat event. No differences were observed in the O2-budget between ambient and warm-acclimated corals and only small fluctuations in host protein, symbiont density and chlorophyll content were detected. In contrast, this lack of differential response, was not mirrored at the cellular level. Warm-acclimated corals had substantially higher 13C enrichment in the host gastrodermis and lipid bodies, but significant lower 15N-nitrate assimilation in the symbionts and the host tissue layers, relative to the ambient-acclimated corals. We discuss potential reasons for the disconnect that occurred between symbiont bicarbonate and nitrate assimilation (in the absence of photosynthetic breakdown) in the warm-acclimated corals. We suggest this represents either a shift in nitrogen utilisation, or supply limitation by the host. Our findings raise several interesting hypotheses regarding the role that nitrogen metabolism plays in thermal stress, which will warrant further investigation if we are to understand the acclimatisation capacity of the coral holobiont.
影响因子：
2.9
作者：
Zor, T;Seliger, Z
通讯作者：
Seliger, Z
影响因子：
4.5
作者：
L. Rodrigues;A. Grottoli
通讯作者：
L. Rodrigues;A. Grottoli
影响因子：
11.6
作者：
Grottoli, Andrea G.;Warner, Mark E.;Matsui, Yohei
通讯作者：
Matsui, Yohei