Desert Dust as a Source of Iron to the Globally Important Diazotroph Trichodesmium.
Desert Dust as a Source of Iron to the Globally Important Diazotroph Trichodesmium.
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沙漠灰尘是全球重要的重18zozotroph trichodesmium的铁的来源。
DOI：
10.3389/fmicb.2017.02683
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发表时间：
2017
影响因子：
5.2
通讯作者：
Bibby TS
中科院分区：
文献类型：
--
作者：
Polyviou D;Baylay AJ;Hitchcock A;Robidart J;Moore CM;Bibby TS
海洋蓝藻Trichodesmium sp。约占每年引入全球海洋的“新”氮的一半，但其生物地理和活性往往受到铁 (Fe) 可用性的限制。公海铁的主要来源是风尘沉积，其中铁主要由颗粒组成，与可溶形式的铁相比，生物利用度较低。我们报告说，当细胞直接生长在作为唯一铁来源的撒哈拉尘埃颗粒附近而不是物理分离时，红毛藻 IMS101 可以提高生长速率和光合生理学，并下调铁胁迫生物标志物基因。这些发现表明，与灰尘相关的铁的不可溶形式的可用性可能取决于细胞接触。转录组分析进一步揭示了所有测试条件下独特的基因表达谱，这意味着木藻具有与从不同来源获取铁相关的独特分子特征。因此，毛藻似乎能够利用特定的机制从海洋系统的复杂来源中获取铁，这有助于解释其作为全球生物地球化学循环中关键微生物的作用。
The marine cyanobacterium Trichodesmium sp. accounts for approximately half of the annual ‘new’ nitrogen introduced to the global ocean but its biogeography and activity is often limited by the availability of iron (Fe). A major source of Fe to the open ocean is Aeolian dust deposition in which Fe is largely comprised of particles with reduced bioavailability over soluble forms of Fe. We report that Trichodesmium erythraeum IMS101 has improved growth rate and photosynthetic physiology and down-regulates Fe-stress biomarker genes when cells are grown in the direct vicinity of, rather than physically separated from, Saharan dust particles as the sole source of Fe. These findings suggest that availability of non-soluble forms of dust-associated Fe may depend on cell contact. Transcriptomic analysis further reveals unique profiles of gene expression in all tested conditions, implying that Trichodesmium has distinct molecular signatures related to acquisition of Fe from different sources. Trichodesmium thus appears to be capable of employing specific mechanisms to access Fe from complex sources in oceanic systems, helping to explain its role as a key microbe in global biogeochemical cycles.