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Photosynthesis

Carbon fix for a diatom

Nature volume 407, pages 959–960 (2000)Cite this article

Water — the elixir of life — is often a scarce resource. Many land plants in warm and arid climates conserve water by temporarily closing their 'breathing tubes', the so-called stomata. This strategy has a drawback, however, in that it reduces the flow of CO2 from the atmosphere into the plant, so lowering its photosynthetic capacity. To solve the dilemma, these plants have devised a mechanism to optimize CO2 uptake. The key component is a CO2 storage and transport compound that contains four carbon atoms and gives this process its name — the C4 pathway. On page 996 of this issue1, Reinfelder and colleagues show for the first time that a marine microalga, the coastal diatom Thalassiosira weissflogii, uses the same C4 pathway as some of its terrestrial counterparts.

But why would a plant suspended in the ocean use a mechanism otherwise employed to conserve water? The answer is simple: just like a terrestrial plant holding its breath, an alga growing in the sea can suffer from a shortage of CO2. Although inorganic carbon is abundant in the sea, 90% of it is in the form of bicarbonate ions (HCO3−). Less than 1% is present as CO2, which is the form required by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the enzyme primarily responsible for photosynthetic carbon fixation.

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Figure 1: Fixation of CO2 in the C4 pathway.

References

  1. Reinfelder, J. R., Kraepiel, A. M. L. & Morel, F. M. M. Nature 407, 996–999 (2000).

    Article  ADS  CAS  Google Scholar 

  2. Badger M. R. et al. Can. J. Bot. 76, 1052– 1071 (1998).

    CAS  Google Scholar 

  3. Sültemeyer, D. Can. J. Bot. 76, 962–972 (1998).

    Google Scholar 

  4. Raven, J. A. Adv. Bot. Res. 27, 85–209 (1997).

    Article  CAS  Google Scholar 

  5. Harris, G. P. Phytoplankton Ecology: Structure, Function, and Fluctuation (Chapman & Hall, London, 1986).

    Book  Google Scholar 

  6. Van den Hoek, C., Mann, D. G. & Jahns, H. M. Algae: An Introduction to Phycology (Cambridge Univ. Press, 1995).

    Google Scholar 

  7. Tortell, P. D. Limnol. Oceanogr. 45, 744–750 (2000).

    Article  ADS  CAS  Google Scholar 

  8. Bruland, K. W. Limnol. Oceanogr. 34, 269–285 (1989).

    Article  ADS  CAS  Google Scholar 

Download references

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  1. Alfred Wegener Institute for Polar and Marine Research, PO Box 120161, Bremerhaven, 27515, Germany

    Ulf Riebesell

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  1. Ulf Riebesell
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Correspondence to Ulf Riebesell.

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Riebesell, U. Carbon fix for a diatom. Nature 407, 959–960 (2000). https://doi.org/10.1038/35039665

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