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Optimizing R ubisco and its regulation for greater resource use efficiency
Author(s) -
CARMOSILVA ELIZABETE,
SCALES JOANNA C.,
MADGWICK PIPPA J.,
PARRY MARTIN A. J.
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12425
Subject(s) - rubisco , photosynthesis , chloroplast , photosynthetic efficiency , photorespiration , assimilation (phonology) , carbon assimilation , chemistry , biology , botany , biochemistry , linguistics , philosophy , gene
Rubisco catalyses the carboxylation of ribulose‐1,5‐bisphosphate ( RuBP ), enabling net CO 2 assimilation in photosynthesis. The properties and regulation of R ubisco are not optimal for biomass production in current and projected future environments. Rubisco is relatively inefficient, and large amounts of the enzyme are needed to support photosynthesis, requiring large investments in nitrogen. The competing oxygenation of RuBP by R ubisco decreases photosynthetic efficiency. Additionally, R ubisco is inhibited by some sugar phosphates and depends upon interaction with R ubisco activase ( R ca) to be reactivated. Rca activity is modulated by the chloroplast redox status and ADP / ATP ratios, thereby mediating R ubisco activation and photosynthetic induction in response to irradiance. The extreme thermal sensitivity of R ca compromises net CO 2 assimilation at moderately high temperatures. Given its central role in carbon assimilation, the improvement of R ubisco function and regulation is tightly linked with irradiance, nitrogen and water use efficiencies. Although past attempts have had limited success, novel technologies and an expanding knowledge base make the challenge of improving R ubisco activity in crops an achievable goal. Strategies to optimize R ubisco and its regulation are addressed in relation to their potential to improve crop resource use efficiency and climate resilience of photosynthesis.