Submitted to: Plant Cell Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2003
Publication Date: 1/29/2004
Citation: Zhu, Y.J., Agbayani, R., Moore, P.H. 2004. Green fluorescent protein, as a positive selection marker, improves the efficiency of papaya (carica papaya l.) transformation while avoiding selection for antibiotic resistance. Plant Cell Reports 22: 660-667. 2004
Interpretive Summary: Genetic engineering of plants holds great promise for increasing crop productivity and quality while reducing inputs of pesticides. However, genetic engineering frequently depends on co-transformation with an antibiotic resistance gene that is perceived by some people to pose a potential risk to human health. Visual selection for fluorescence expressed by a transformed green fluorescent protein (GFP) gene was found in a collaborative project between scientists of ARS and the Hawaii Agriculture Research Center to be more efficient than selection for ability to grow in the presence of antibiotics. These results open the way for improving the efficiency of genetic engineering of plants while avoiding perceived problems with use of antibiotic resistance genes.
Technical Abstract: Chemical-based selection for plant transformation is associated with a number of real and perceived problems that might be avoided through visual selection. We used green fluorescent protein, GFP, as a visual selectable marker to produce transformed papaya (Carica papaya) plants following microprojectile bombardment of embryogenic callus. GFP selection reduced the selection time to 3 to 4 weeks compared to a 3-month selection time on a geneticin (G418) antibiotic containing medium. Moreover, GFP selection increased the number of transformed papaya plants by about 6-fold compared to selection in the presence of antibiotics. Overall, use of GFP for selection of transgenic papaya lines improved our throughput for transformation by about 18-fold, while avoiding drawbacks associated with use of antibiotic resistance-based selection markers.