An overview of over-expression of C4-cycle enzymes into C3 plants

Abstract

An overview of biochemical and physiological consequences of the over expression of C4 -cycle genes in C3 plant are presented. The methodology, based on the evolutionary situation, has enabled enzymes involved in the C4 pathway to be expressed at high levels and in required sites in the leaves of C3 plants. Even though overproduction of a single C4 enzyme can modify the carbon metabolism of C3 plants, it does not show any positive effects on photosynthesis. Transgenic C3 plants overproducing multiple enzymes are now being produced for improving the photosynthetic performance of C3 plants. The results show that a combined over expression of C4 -cycle genes could supply additional information on whether or not these enzymes may work in concert. Single over expression of C4 -cycle genes might perturb metabolism, as all C4 enzyme also have individual functions in c3 plants. The analysis of double and multiple transformants might help to highlight the possibility of the approach to create a single cell C4 cycle in C3 crops.