How do marine diatoms fix 10 billion tonnes of inorganic carbon per year?
How do marine diatoms fix 10 billion tonnes of inorganic carbon per year?
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DOI：
10.1139/b05-077
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发表时间：
2005-07-01
期刊：
影响因子：
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通讯作者：
Leegood, RC
中科院分区：
文献类型：
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作者：
Granum, E;Raven, JA;Leegood, RC
硅藻是负责至少四分之一的无机碳固定每年在海洋中。尽管在过去的30年里进行了大量的研究，但海洋硅藻对无机碳的同化仍有一些基本的未解决的问题。目前尚不清楚碳浓缩机制是如何运作的，以及它是基于直接获得无机碳还是基于C-4途径，还是两者兼而有之。虽然C-4途径的运作证据正在积累，但负责“C-3 + C-1”无机碳同化的酶在光照和黑暗中的作用仍然存在争议。在这篇综述中，我们讨论了硅藻是否具有C-4型CO2浓缩机制所需的酶和结构成分。这些进行了比较和对比与其他C-4系统，无论是单细胞和陆生植物，这是基于克兰茨解剖。新的数据表达的基因，可能参与C-4光合作用，包括磷酸烯醇式丙酮酸羧化酶和磷酸烯醇式丙酮酸羧激酶。
Diatoms are responsible for at least a quarter of inorganic carbon fixed each year in the ocean. Despite very considerable research over the last 30 years, there are still a number of fundamental unresolved aspects of inorganic carbon assimilation by marine diatoms. It is not clear how the carbon-concentrating mechanism functions and whether it is based on the direct acquisition of inorganic carbon or on a C-4 pathway, or a combination of both. Although evidence for the operation of a C-4 pathway is accumulating, the role(s) of the enzyme(s) responsible for "C-3 + C-1" inorganic carbon assimilation in the light and dark are still matters of controversy. In this review, we discuss whether diatoms possess the enzymic and structural components necessary for a C-4-type CO2-concentrating mechanism. These are compared and contrasted with other C-4 systems, both single-celled and those in terrestrial plants, which are based on Kranz anatomy. New data are presented on expression of genes that might be involved in C-4 photosynthesis, including phosphoenolpyruvate carboxylase and phosphoenolpyruvate carboxykinase.