Influence of CO2, nitrate, phosphate, and silicate limitation on intracellular dimethylsulfoniopropionate in batch cultures of the coastal diatom Thalassiosira pseudonana
Influence of CO2, nitrate, phosphate, and silicate limitation on intracellular dimethylsulfoniopropionate in batch cultures of the coastal diatom Thalassiosira pseudonana
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DOI：
10.4319/lo.2003.48.6.2256
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发表时间：
2003-11-01
影响因子：
4.5
通讯作者：
Sunda, WG
中科院分区：
文献类型：
--
作者：
Bucciarelli, E;Sunda, WG
我们测量了沿海硅藻假微型海链藻营养有限的分批培养物中的细胞内磺基丙酸二甲酯 (DMSP) 浓度。在 N、P、CO2 和 Si 生长限制下，细胞内 DMSP 浓度在生长指数期降至较低值，并在营养限制下增加。细胞内 DMSP 浓度随着生长速率和细胞叶绿素 a 的降低而呈指数增加，以响应营养限制的类型和程度。对于给定的生长速率，N 限制的细胞显示细胞 DMSP 浓度的最大增加，CO2 和 Si 的限制具有中间效果，而 P 的限制导致细胞 DMSP 浓度的增加最小。结果证明了营养限制对于提高海藻中 DMSP 浓度的重要性。这种增强可能部分与 DMSP 作为细胞抗氧化剂的作用以及营养限制期间细胞内氧化应激的增加有关。用 DMSP（一种含硫渗透剂）替代含氮渗透剂（例如脯氨酸）也可以解释至少部分氮限制下 DMSP 的增加。我们的结果还指出了硅藻华在全球或区域硫循环中可能的重要性。
We measured intracellular dimethyl sulfoniopropionate (DMSP) concentrations in nutrient-limited batch cultures of the coastal diatom Thalassiosira pseudonana. Under N, P, CO2, and Si growth limitation, intracellular DMSP concentrations decreased to low values during the exponential phase of growth and increased under nutrient limitation. The intracellular DMSP concentration increased exponentially with decreasing growth rate and cellular chlorophyll a, in response to the type and degree of nutrient limitation. For a given growth rate, N-limited cells showed the greatest increase in cellular DMSP concentrations, CO2 and Si limitation had an intermediate effect, and P limitation caused-the smallest increase. The results demonstrate the importance of nutrient limitation in enhancing DMSP concentrations in marine algae. This enhancement may be linked in part to the role of DMSP as a cellular antioxidant and to increased oxidative stress within cells during nutrient limitation. The replacement of DMSP, a sulfur-containing osmolyte, for N-containing osmolytes such as proline may also explain at least some of the DMSP increase under N limitation. Our results also point to the possible importance of diatom blooms in global or regional sulfur cycles.