Environmentally driven evolution of Rubisco and improved photosynthesis and growth within the C3 genus Limonium (Plumbaginaceae)

• Published in: The New phytologist Vol. 203; no. 3; pp. 989 - 999
• Main Authors: Galmés, Jeroni, Andralojc, P. John, Kapralov, Maxim V., Flexas, Jaume, Keys, Alfred J., Molins, Arántzazu, Parry, Martin A. J., Conesa, Miquel À.
• Format: Journal Article
• Language: English
• Published: England New Phytologist Trust 01.08.2014; Wiley Subscription Services, Inc
• Subjects: Accumulation; Amino acids; Assimilation; Biocatalysis; Biological evolution; Biomass; Carbon - metabolism; Carbon dioxide; Carbon Dioxide - metabolism; Carbon fixation; carboxylase catalytic efficiency; Carboxylation; Drought; Environment; Evolution; Evolution, Molecular; Geography; Haplotypes; improved photosynthesis; Kinetics; Limonium; Mediterranean; Molecular evolution; Molecular Sequence Data; Oxygenase; Photosynthesis; Plant biomass; Plant Leaves - physiology; Plants; Plumbaginaceae - enzymology; Plumbaginaceae - growth & development; Positive selection; Protein Subunits - metabolism; Ribulose-bisphosphate carboxylase; Ribulose-Bisphosphate Carboxylase - metabolism; Rubisco; Spain; Species; Species Specificity; Temperature; water stress; Spain; Mediterranean; improved photosynthesis; carboxylase catalytic efficiency; Limonium; drought; water stress; Rubisco; evolution
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12858

Carbon assimilation by most ecosystems requires ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Its kinetic parameters are likely to have evolved in parallel with intracellular CO2 availability, with the result that faster forms of Rubisco occur in species with CO2-concentrating mechanisms. The Rubisco catalytic properties were determined and evaluated in relation to growth and carbon assimilation capacity in Mediterranean Limonium species, inhabiting severe stress environments. Significant kinetic differences between closely related species depended on two amino acid substitutions at functionally important residues 309 and 328 within the Rubisco large subunit. The Rubisco of species facing the largest CO2 restrictions during drought had relatively high affinity for CO2 (low Michaelis–Menten constant for CO2 (K c)) but low maximum rates of carboxylation ( ), while the opposite was found for species that maintained higher CO2 concentrations under similar conditions. Rubisco kinetic characteristics were correlated with photosynthetic rate in both well-watered and drought-stressed plants. Moreover, the drought-mediated decrease in plant biomass accumulation was consistently lower in species with higher Rubisco carboxylase catalytic efficiency ( ). The present study is the first demonstration of Rubisco adaptation during species diversification within closely related C3 plants, revealing a direct relationship between Rubisco molecular evolution and the biomass accumulation of closely related species subjected to unfavourable conditions.