Accessibility navigation


The role of Rubisco kinetics and pyrenoid morphology in shaping the CCM of haptophyte microalgae

Heureux, A. M. C., Young, J. N., Whitney, S. M., Eason-Hubbard, M. R., Lee, R. B. Y., Sharwood, R. E. and Rickaby, R. E. M. (2017) The role of Rubisco kinetics and pyrenoid morphology in shaping the CCM of haptophyte microalgae. Journal of Experimental Botany, 68 (14). pp. 3959-3969. ISSN 0022-0957

[img]
Preview
Text (Open Access) - Published Version
· Available under License Creative Commons Attribution.
· Please see our End User Agreement before downloading.

643kB

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1093/jxb/erx179

Abstract/Summary

The haptophyte algae are a cosmopolitan group of primary producers that contribute significantly to the marine carbon cycle and play a major role in paleo-climate studies. Despite their global importance, little is known about carbon assimilation in haptophytes, in particular the kinetics of their Form 1D CO2-fixing enzyme, Rubisco. Here we examine Rubisco properties of three haptophytes with a range of pyrenoid morphologies (Pleurochrysis carterae, Tisochrysis lutea, and Pavlova lutheri) and the diatom Phaeodactylum tricornutum that exhibit contrasting sensitivities to the trade-offs between substrate affinity (Km) and turnover rate (kcat) for both CO2 and O2. The pyrenoid-containing T. lutea and P. carterae showed lower Rubisco content and carboxylation properties (KC and kCcat) comparable with those of Form 1D-containing non-green algae. In contrast, the pyrenoid-lacking P. lutheri produced Rubisco in 3-fold higher amounts, and displayed a Form 1B Rubisco kCcat–KC relationship and increased CO2/O2 specificity that, when modeled in the context of a C3 leaf, supported equivalent rates of photosynthesis to higher plant Rubisco. Correlation between the differing Rubisco properties and the occurrence and localization of pyrenoids with differing intracellular CO2:O2 microenvironments has probably influenced the divergent evolution of Form 1B and 1D Rubisco kinetics.

Item Type:Article
Refereed:Yes
Divisions:Faculty of Life Sciences > School of Biological Sciences > Biomedical Sciences
Faculty of Life Sciences > School of Biological Sciences > Ecology and Evolutionary Biology
ID Code:71132
Publisher:Oxford University Press

Downloads

Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation