PHOTOSYNTHETICA

Photosynthetica 2011, 49(4):481-496 | DOI: 10.1007/s11099-011-0078-z

CO₂ sequestration in plants: lesson from divergent strategies

S. K. Vats^1,*, S. Kumar², P. S. Ahuja¹

¹ Biodiversity Divisions, Institute of Himalayan Bioresource Technology, Palampur, India

² Biotechnology Divisions, Institute of Himalayan Bioresource Technology, Palampur, India

Most organisms inhabiting earth feed directly or indirectly on the products synthesized by the reaction of photosynthesis, which at the current atmospheric CO₂ levels operates only at two thirds of its peak efficiency. Restricting the photorespiratory loss of carbon and thereby improving the efficiency of photosynthesis is seen by many as a good option to enhance productivity of food crops. Research during last half a century has shown that several plant species developed CO₂-concentrating mechanism (CCM) to restrict photorespiration under lower concentration of available CO₂. CCMs are now known to be operative in several terrestrial and aquatic plants, ranging from most advanced higher plants to algae, cyanobacteria and diatoms. Plants with C₄ pathway of photosynthesis (where four-carbon compound is the first product of photosynthesis) or crassulacean acid metabolism (CAM) may consistently operate CCM. Some plants however can undergo a shift in photosynthetic metabolism only with change in environmental variables. More recently, a shift in plant photosynthetic metabolism is reported at high altitude where improved efficiency of CO₂ uptake is related to the recapture of photorespiratory loss of carbon. Of the divergent CO₂ assimilation strategies operative in different oraganisms, the capacity to recapture photorespiratory CO₂ could be an important approach to develop plants with efficient photosynthetic capacity.

Keywords: aquatic; carbon-concentrating mechanisms; crassulacean acid metabolism; C₄ photosynthesis; Rubisco

Received: February 22, 2011; Accepted: September 4, 2011; Published: December 1, 2011Show citation