ABSTRACT
C4 plants are considered to be more versatile when compared with C3 plants in terms of their productivity and innate ability to withstand abiotic stress. This is because they exhibit reduced photorespiration owing to the Kranz anatomical structure of their leaf and increased water use and nitrogen assimilation efficiencies. Efforts have been made by researchers in transferring genes from C4 plants that are responsible for carbon dioxide assimilation and photosynthesis, leading to elevated carbon dioxide levels. Overexpression of the C4 photosynthetic genes, namely, phosphoenol pyruvate carboxylase, pyruvate, orthophosphate dikinase, and NADP-ME can increase the photosynthetic efficiency in C3 plants like Arabidopsis, tobacco, rice, wheat, and potato. These genes also increased the resistance of the C3 plants to abiotic stress. The elevated carbon dioxide levels resulted in increased crop productivity and thereby yield. The C4 photosynthetic genes are also involved in reducing global warming and are implicated in the global climate change. This chapter highlights the importance of C4, C3, and Crassulacean 194acid metabolism plants, their advantages over each other and the strategies to develop transgenic C3 plants harbouring C4 genes and having an increased photosynthetic efficiency and carbon assimilation, thereby increasing the productivity to meet global needs. This chapter also aims to highlight the importance of genetic engineering of C3 plants in the aspect of how it might impact the global climate change.
