Glucose uptake and its effect on gene expression in prochlorococcus.
Glucose uptake and its effect on gene expression in prochlorococcus.
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DOI：
10.1371/journal.pone.0003416
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发表时间：
2008
期刊：
影响因子：
3.7
通讯作者：
García-Fernández JM
中科院分区：
文献类型：
--
作者：
Gómez-Baena G;López-Lozano A;Gil-Martínez J;Lucena JM;Diez J;Candau P;García-Fernández JM
海洋蓝藻原绿球藻被认为是光合自养微生物，尽管从未专门讨论过它们对外源糖的利用。我们研究了不同高辐照度和低辐照度适应原绿球菌菌株的葡萄糖摄取，以及添加葡萄糖对几个葡萄糖相关基因表达的影响。通过向原绿球菌培养物中添加放射性标记的葡萄糖，然后通过流式细胞术结合细胞分选来测量葡萄糖摄取，以便将原绿球菌细胞与细菌污染物分离。通过过滤回收分选的细胞并测量它们的放射性。添加葡萄糖后，使用 rnpB 基因作为内部对照，通过半定量实时 RT-PCR 测定低辐照适应原绿球藻 SS120 菌株中几个基因（涉及葡萄糖代谢、氮同化及其调节）的表达。我们的结果首次证明，这项工作中研究的原绿球藻菌株以显着的速率吸收葡萄糖，即使浓度接近海洋中的浓度，并且还排除了最终细菌污染物进行这种吸收的可能性，因为仅使用原绿球藻细胞进行放射性测量。此外，我们还发现，在 SS120 菌株的培养物中添加葡萄糖后，许多与葡萄糖利用相关的基因（即 zwf、gnd 和 dld，分别编码葡萄糖-6-磷酸脱氢酶、6-磷酸葡萄糖酸脱氢酶和乳酸脱氢酶）的表达显着增加。这一事实与葡萄糖摄取量一起，清楚地表明了该现象的生理重要性。鉴于原绿球藻对全球初级生产的重大贡献，这些发现对于理解浮游植物在自然界碳循环中的作用具有重要意义。此外，同化碳分子的能力可以为理解原绿球藻的生态成功提供额外的线索。
The marine cyanobacteria Prochlorococcus have been considered photoautotrophic microorganisms, although the utilization of exogenous sugars has never been specifically addressed in them. We studied glucose uptake in different high irradiance- and low irradiance-adapted Prochlorococcus strains, as well as the effect of glucose addition on the expression of several glucose-related genes. Glucose uptake was measured by adding radiolabelled glucose to Prochlorococcus cultures, followed by flow cytometry coupled with cell sorting in order to separate Prochlorococcus cells from bacterial contaminants. Sorted cells were recovered by filtration and their radioactivity measured. The expression, after glucose addition, of several genes (involved in glucose metabolism, and in nitrogen assimilation and its regulation) was determined in the low irradiance-adapted Prochlorococcus SS120 strain by semi-quantitative real time RT-PCR, using the rnpB gene as internal control. Our results demonstrate for the first time that the Prochlorococcus strains studied in this work take up glucose at significant rates even at concentrations close to those found in the oceans, and also exclude the possibility of this uptake being carried out by eventual bacterial contaminants, since only Prochlorococcus cells were used for radioactivity measurements. Besides, we show that the expression of a number of genes involved in glucose utilization (namely zwf, gnd and dld, encoding glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and lactate dehydrogenase, respectively) is strongly increased upon glucose addition to cultures of the SS120 strain. This fact, taken together with the magnitude of the glucose uptake, clearly indicates the physiological importance of the phenomenon. Given the significant contribution of Prochlorococcus to the global primary production, these findings have strong implications for the understanding of the phytoplankton role in the carbon cycle in nature. Besides, the ability of assimilating carbon molecules could provide additional hints to comprehend the ecological success of Prochlorococcus.
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DOI：
10.1016/s0967-0637(99)00108-9
发表时间：
2000-07-01
影响因子：
2.4
作者：
Goericke, R;Olson, RJ;Shalapyonok, A
通讯作者：
Shalapyonok, A
影响因子：
4.2
作者：
López-Lozano, A;Diez, J;García-Fernández, JM
通讯作者：
García-Fernández, JM
影响因子：
4.5
作者：
Fuller, NJ;West, NJ;Scanlan, DJ
通讯作者：
Scanlan, DJ
影响因子：
11.4
作者：
LUQUE, I;FLORES, E;HERRERO, A
通讯作者：
HERRERO, A
影响因子：
4.5
作者：
Kettler GC;Martiny AC;Huang K;Zucker J;Coleman ML;Rodrigue S;Chen F;Lapidus A;Ferriera S;Johnson J;Steglich C;Church GM;Richardson P;Chisholm SW
通讯作者：
Chisholm SW