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Plant physiologists set about comprehending the genesis of the C4 photosynthetic pathway after its discovery by Hatch and Slack. They discovered that a sophisticated combination of morphological and biochemical adaptations allowed the plant to concentrate CO2 around RuBisCO to achieve maximum efficiency. We categorize the evolutionary events leading to C4 photosynthesis, beginning with anoxygenic photosynthesis and the evolution of RuBisCO to the cooling of Earth by the Great Oxygenation Event that led to the oxygenic photosynthesis. The evolutionary descent of the C4 plants is a phenomenon that occurred around 30 million years ago. Due to industrialization and population growth, improved photosynthetic efficiency and carbon fixation of C4 plants could contest the current global scenario of rising CO2 concentration. C3 crops engineered with C4 traits, implemented on a large scale, could impact the climate globally. Here we discuss the various strategies used to introduce C4 traits in the C3 plants and the potential techniques to be considered for successful hybridization. [ABSTRACT FROM AUTHOR]

Transgenic potato ( Solanum tuberosum L. cv. Desiree) plants expressing components of a novel cyanobacterial photorespiratory glycolate catabolism pathway were developed. Transgenic plant expressing glcD1 (glycolate dehydrogenase I) gene was referred to as synGDH and transgenic plants expressing gcl (glyoxylate carboligase) and tsr (tartronic semialdehyde reductase) genes simultaneously were designated as synGT. Both synGDH and synGT plants showed stable gene transformation, integration and expression. Enhanced glyoxylate contents in synGDH plants were detected as compared to synGT and non-transgenic (NT) plants. Phenotypic evaluation revealed that synGDH plants accumulated 11 % higher dry weight, while, tuber weight was 38 and 16 % higher than NT and synGT, respectively. Upon challenging the plants in high temperature and high light conditions synGDH plants maintained higher Fv/ Fm and showed less bleaching of chlorophyll as compared to synGT and NT plants. These results indicate that genetic transformation of complete pathway in one plant holds promising outcomes in terms of biomass accumulation to meet future needs for food and energy. [ABSTRACT FROM AUTHOR]