Intragenic modification of maize.

The discovery of plant DNA recombination techniques triggered the development of a wide range of genetically modified crops. The transgenics were the first generation of modified plants; however， these crops were quickly questioned due to the artificial combination of DNA between different species. As a result， the second generation of modified plants known as cisgenic and/or intragenic crops arose as an alternative to genetic plant engineering. Cisgenic and/or intragenic crops development establishes the combination of DNA from the plant itself or related species avoiding the introduction of foreign genetic material， such as selection markers and/or reporter genes. Nowadays it has been made successful cisgenic and/or intragenic modifications in crops such as potato and apple. The present study shows the possibility of reaching similar approach in corn plants. This research was focused on achieve intragenic overexpression of the maize Rubisco activase (Rca) protein. The results were compared with changes in the expression of the same protein， in maize plants grown after 23 cycles of conventional selection and open field planting. Experimental evidence shows that maize intragenic modification is possible for increasing specific gene expression， preserving plant genome free of foreign DNA and achieving further significant savings in time and man labor for crop improvement.