Reduced expression of the rate-limiting carbon fixation enzyme RuBisCO in the benthic foraminifer Baculogypsina sphaerulata holobiont in response to heat shock
Reduced expression of the rate-limiting carbon fixation enzyme RuBisCO in the benthic foraminifer Baculogypsina sphaerulata holobiont in response to heat shock
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DOI：
10.1016/j.jembe.2012.06.025
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发表时间：
2012-11-01
影响因子：
2
通讯作者：
Fan, Tung-Yung
中科院分区：
文献类型：
--
作者：
Doo, Steve S.;Mayfield, Anderson B.;Fan, Tung-Yung
Baculogypsina sphaerulata (Parker and Jones, 1860) 是一种常见的大型底栖有孔虫 (LBF)，是珊瑚礁生态系统中重要的钙化剂。由于人们担心全球气温升高可能会损害该物种的生存，该物种与硅藻菱形藻形成了共生关系，因此我们研究了来自台湾小琉球岛潮间带藻坪的 B. sphaerulata holobiont 对热休克的反应。 B. sphaerulata 标本在 26（环境）、28、30、32 或 34 摄氏度下孵育 5 小时，旨在模拟低潮时地面暴露所产生的高温短脉冲。为了评估分子水平的反应，我们测量了硅藻共生体中核酮糖 1-5-二磷酸羧化酶/加氧酶 (RuBisCO) 蛋白的表达。在高于环境温度 34°C/8°C 的条件下培养的球形 B. sphaerulata holobionts 中，这种限速碳固定酶的表达显着下降（与对照相比下降了 50%），但表达对升温水平具有弹性。比环境温度高 6 摄氏度。这表明，暴露于自然界中偶尔经历的高温可能会降低硅藻共生体的碳固定能力。鉴于光合作用和碳固定在这些海洋钙化物中的重要性，这些数据表明气候驱动的海洋变暖可能对 B. sphaerulata holobiont 产生有害影响。 (C) 2012 Elsevier B.V. 保留所有权利。
Baculogypsina sphaerulata (Parker and Jones, 1860) is a common large benthic foraminifer (LBF) and is an important calcifier in coral reef ecosystems. As there are concerns that global increasing temperatures may compromise the survival of this species, which forms a symbiotic relationship with the diatom Nitzschia sp., we investigated the response of the B. sphaerulata holobiont from the intertidal algal flats of Xiao Liu Chiu Island, Taiwan to heat shock B. sphaerulata specimens were incubated at 26 (ambient), 28, 30, 32, or 34 degrees C for 5 h designed to simulate short pulses of elevated temperature that occur in situ from subaerial exposure at low tide. To assess the molecular-level response, we measured the expression of the ribulose 1-5-bisphosphate carboxylase/oxygenase (RuBisCO) protein in the diatom symbiont There was a significant decrease in expression of this rate-limiting carbon fixation enzyme in B. sphaerulata holobionts incubated at 34 degrees C/8 degrees C above ambient (similar to 50% decline relative to controls), but expression was resilient to levels of warming up to 6 degrees C above ambient. This suggests that exposure to high temperatures occasionally experienced in nature may diminish the capacity for carbon fixation of the diatom symbiont. Given the importance of photosynthesis and carbon fixation in these marine calcifiers, these data suggest that climate-driven ocean warming may exert deleterious effects on the B. sphaerulata holobiont. (C) 2012 Elsevier B.V. All rights reserved.