Kapralov, MV and Smith, JA and Filatov, DA (2012) Rubisco evolution in C₄ eudicots: an analysis of Amaranthaceae sensu lato. PLoS One, 7 (12). ISSN 1932-6203
Rubisco evolution in C₄ eudicots: an analysis of Amaranthaceae sensu lato..pdf - Published Version
Available under License Creative Commons Attribution.
BACKGROUND: Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) catalyses the key reaction in the photosynthetic assimilation of CO₂. In C₄ plants CO₂ is supplied to Rubisco by an auxiliary CO₂-concentrating pathway that helps to maximize the carboxylase activity of the enzyme while suppressing its oxygenase activity. As a consequence, C₄ Rubisco exhibits a higher maximum velocity but lower substrate specificity compared with the C₃ enzyme. Specific amino-acids in Rubisco are associated with C₄ photosynthesis in monocots, but it is not known whether selection has acted on Rubisco in a similar way in eudicots. METHODOLOGY/PRINCIPAL FINDINGS: We investigated Rubisco evolution in Amaranthaceae sensu lato (including Chenopodiaceae), the third-largest family of C₄ plants, using phylogeny-based maximum likelihood and Bayesian methods to detect Darwinian selection on the chloroplast rbcL gene in a sample of 179 species. Two Rubisco residues, 281 and 309, were found to be under positive selection in C₄ Amaranthaceae with multiple parallel replacements of alanine by serine at position 281 and methionine by isoleucine at position 309. Remarkably, both amino-acids have been detected in other C₄ plant groups, such as C₄ monocots, illustrating a striking parallelism in molecular evolution. CONCLUSIONS/SIGNIFICANCE: Our findings illustrate how simple genetic changes can contribute to the evolution of photosynthesis and strengthen the hypothesis that parallel amino-acid replacements are associated with adaptive changes in Rubisco.
|Uncontrolled Keywords:||MD Multidisciplinary|
|Subjects:||Q Science > QH Natural history > QH301 Biology
Q Science > QH Natural history > QH426 Genetics
|Divisions:||Natural Sciences and Psychology|
|Publisher:||Public Library of Science|
|Date Deposited:||20 May 2015 14:53|
|Last Modified:||20 May 2015 14:53|
|DOI or Identification number:||10.1371/journal.pone.0052974|
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