Expression of Silencing-Suppressor Protein Enhances the Performance of an Engineered Metabolic Pathway
Expression of a transgene can dwindle over time due to the plant's silencing pathways. These have evolved as an antiviral defense, and viruses have co-evolved viral silencing-suppressor proteins (VSPs) to block them. VSPs have then been used with transgene constructs to enhance its expression. However, it usually causes developmental abnormalities.
Fatima Naim of the University of Sydney in Australia, together with her colleagues evaluated a number of different VSPs expressed in the seeds of Arabidopsis thaliana alongside a transgenic pathway for arachidonic acid (AA), polyunsaturated fatty acid.
Results from independent transgenic events, maintained for four generations, showed that the VSP-AA-transformed plants were normal and could produce 40% more AA than plants transformed with the AA transgene alone. A geminivirus VSP, V2, was also found to be expressed without causing developmental defects and gave strong transgene enhancement. These results demonstrate that VSP expression can be used to protect and enhance stable transgene performance.
For more information, read the article in Plant Biotechnology Journal.
This article is part of the Crop Biotech Update, a weekly summary of world developments in agri-biotech for developing countries, produced by the Global Knowledge Center on Crop Biotechnology, International Service for the Aquisition of Agri-Biotech Applications SEAsiaCenter (ISAAA)