Iron Availability Influences Silicon Isotope Fractionation in Two Southern Ocean Diatoms (Proboscia inermis and Eucampia antarctica) and a Coastal Diatom (Thalassiosira pseudonana)
Iron Availability Influences Silicon Isotope Fractionation in Two Southern Ocean Diatoms (Proboscia inermis and Eucampia antarctica) and a Coastal Diatom (Thalassiosira pseudonana)
复制标题
铁的有效性影响两种南大洋硅藻（Proboscia inermis 和 Eucampia antarctica）和沿海硅藻（Thalassiosira fakenana）的硅同位素分馏
DOI：
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发表时间：
2017
影响因子：
3.7
通讯作者：
R. Strzepek
中科院分区：
文献类型：
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作者：
Scott W. Meyerink;M. Ellwood;W. Maher;R. Strzepek
硅（Si）同位素的分馏测量两个南大洋硅藻（Proboscia inermis和南极洲Eucampia）和沿海硅藻（Thalassiosira dangerana），生长在不同的铁（Fe）浓度。不同Fe浓度对T. Escherichia，而E.在Fe-充分和Fe-限制条件之间，anaerotica和P. inermis的e值表现出显著的变化。无芒刺和E.抗氧化剂从富铁条件下的（± 1 SD）-1.11 ± 0.15‰和-1.42 ± 0.41‰下降到限铁条件下的（± 1 SD）-1.38 ± 0.27‰和-1.57 ± 0.5‰。这些变化可能是由于硅藻适应环境的营养状况而产生的。T. Escheriana是一个沿海的克隆，通常习惯于低硅，但高铁的条件下，而E。anaerotica和P. inermis通常习惯于高Si、高硝酸盐、低Fe条件。生长诱导的Fe限制引起的硅酸（Si（OH）4）吸收的变化是导致E中Si同位素变化的可能机制。anaerotica和P. inermis。物种多样性和资源限制（如Fe）对硅藻硅同位素分馏的倍增效应可能会改变硅藻质沉积物和海面Si（OH）4中硅藻蛋白石的硅同位素组成。这项工作突出了需要进一步在体外研究的细胞内机制参与Si（OH）4的摄取，以及相关的途径硅同位素分馏硅藻。
The fractionation of silicon (Si) isotopes was measured in two Southern Ocean diatoms (Proboscia inermis and Eucampia Antarctica) and a coastal diatom (Thalassiosira pseudonana) that were grown under varying iron (Fe) concentrations. Varying Fe concentrations had no effect on the Si isotope enrichment factor (e) in T. pseudonana, whilst E. antarctica and P. inermis exhibited significant variations in the value of e between Fe-replete and Fe-limited conditions. Mean e values in P. inermis and E. antarctica decreased from (± 1SD) -1.11 ± 0.15‰ and -1.42 ± 0.41‰ (respectively) under Fe-replete conditions, to -1.38 ± 0.27‰ and -1.57 ± 0.5‰ (respectively) under Fe-limiting conditions. These variations likely arise from adaptations in diatoms arising from the nutrient status of their environment. T. pseudonana is a coastal clone typically accustomed to low Si but high Fe conditions whereas E. antarctica and P. inermis are typically accustomed to High Si, High nitrate low Fe conditions. Growth induced variations in silicic acid (Si(OH)4) uptake arising from Fe-limitation is the likely mechanism leading to Si-isotope variability in E. antarctica and P. inermis. The multiplicative effects of species diversity and resource limitation (e.g. Fe) on Si-isotope fractionation in diatoms can potentially alter the Si-isotope composition of diatom opal in diatamaceous sediments and sea surface Si(OH)4. This work highlights the need for further in-vitro studies into intracellular mechanisms involved in Si(OH)4 uptake, and the associated pathways for Si-isotope fractionation in diatoms.