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The CO 2 concentrating mechanism and photosynthetic carbon assimilation in limiting CO 2 : how Chlamydomonas works against the gradient
Author(s) -
Wang Yingjun,
Stessman Dan J.,
Spalding Martin H.
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12829
Subject(s) - rubisco , chlamydomonas , photosynthesis , photorespiration , carbon fixation , limiting , assimilation (phonology) , carbon assimilation , total inorganic carbon , ribulose , carbon dioxide , carbon fibers , photosynthetic efficiency , oxygenase , chemistry , botany , biology , biochemistry , biophysics , ecology , materials science , gene , mechanical engineering , linguistics , philosophy , composite number , mutant , engineering , composite material
Summary The CO 2 concentrating mechanism ( CCM ) represents an effective strategy for carbon acquisition that enables microalgae to survive and proliferate when the CO 2 concentration limits photosynthesis. The CCM improves photosynthetic performance by raising the CO 2 concentration at the site of ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco), simultaneously enhancing carbon fixation and suppressing photorespiration. Active inorganic carbon (Ci) uptake, Rubisco sequestration and interconversion between different Ci species catalyzed by carbonic anhydrases ( CA s) are key components in the CCM , and an array of molecular regulatory elements is present to facilitate the sensing of CO 2 availability, to regulate the expression of the CCM and to coordinate interplay between photosynthetic carbon metabolism and other metabolic processes in response to limiting CO 2 conditions. This review intends to integrate our current understanding of the eukaryotic algal CCM and its interaction with carbon assimilation, based largely on Chlamydomonas as a model, and to illustrate how Chlamydomonas acclimates to limiting CO 2 conditions and how its CCM is regulated.