Extremely heat tolerant photo-symbiosis in a shallow marine benthic foraminifera
Extremely heat tolerant photo-symbiosis in a shallow marine benthic foraminifera
复制标题
浅海底栖有孔虫的极耐热光共生
作者：
C. Schmidt;D. Titelboim;J. Brandt;B. Herut;S. Abramovich;A. Almogi‐Labin;M. Kučera
漂白，藻类共生体的损失，发生在海水温度最低限度地超过平均夏季SST（海面温度）的海洋光共生生物。预适应允许生物体在温暖的条件下生存，前提是这种耐受性可以带到新的栖息地。在这里，我们提供的证据存在这样的适应底栖有孔虫Pararotalia calcariformata。该物种生活在地中海的一个热污染地区，夏季水温最高，日平均温度为36 °C。为了测试这种情况是否代表广泛的适应，我们进行了操纵实验，将该物种从未污染的地点暴露于高温（20-42 °C）。在两个实验中（20-36 °C），将其与更热敏感的有孔虫Amphistegina lobifera共培养。光合活性降低。在32 °C下出现了裂叶藻光化学胁迫，而在36 °C下首次观察到了石灰状假单胞菌的光化学胁迫。Calcariformata在所有处理条件下均存活，并在36 °C下生长。光共生在P. calcariformata是不寻常的耐热性。这些观察结果意味着，海洋真核生物-真核生物光共生可以通过利用自然发生的预适应池来对升高的温度做出反应。它还提供了一个角度来看，大量的共生轴承有孔虫出现在早新生代温室气候。
Bleaching, the loss of algal symbionts, occurs in marine photosymbiotic organisms at water temperatures minimally exceeding average summer SST (sea surface temperatures). Pre-adaptation allows organisms to persist under warmer conditions, providing the tolerance can be carried to new habitats. Here we provide evidence for the existence of such adaptation in the benthic foraminifera Pararotalia calcariformata. This species occurs at a thermally polluted site in the Mediterranean, where water temperatures reach a maxima daily average of 36 °C during the summer. To test whether this occurrence represents a widespread adaptation, we conducted manipulative experiments exposing this species from an unpolluted site to elevated temperatures (20–42 °C). It was kept in co-culture with the more thermally sensitive foraminifera Amphistegina lobifera in two experiments (20–36 °C). Reduced photosynthetic activity in A. lobifera occurred at 32 °C whereas photochemical stress in P. calcariformata was first observed during exposure to 36 °C. Pararotalia calcariformata survived all treatment conditions and grew under 36 °C. The photosymbiosis in P. calcariformata is unusually thermally tolerant. These observations imply that marine eukaryote-eukaryote photosymbiosis can respond to elevated temperatures by drawing on a pool of naturally occurring pre-adaptations. It also provides a perspective on the massive occurrence of symbiont-bearing foraminifera in the early Cenozoic hothouse climate.
持续变暖趋势促进了共生有孔虫副轮虫最近入侵东地中海
影响因子：
3.7
作者：
Mouanga;Langer M.R.
通讯作者：
Langer M.R.