W560 Chloroplast Genomics and Genetic Engineering for Crop Improvement and Bioreactors for Biopharmaceuticals, Biofuels and Vaccines

Date: Monday, January 16, 2012
Time: 1:50 PM
Room: Town and Country
Henry Daniell , University of Central Florida, College of Medicine, Orlando, FL
Chloroplast transformation has several unique advantages including high levels of expression and transgene containment via maternal inheritance of chloroplast genomes or by harvesting products from vegetative tissues before appearance of reproductive structures. The highest levels of expression in the published literature for engineering agronomic traits or human therapeutic proteins or industrial products were indeed achieved using this concept. In addition, this concept offers a number of other unique advantages including multi-gene engineering, lack of gene silencing or position effects due to site specific transgene integration and minimal or elimination of pleiotropic effects.

Tobacco chloroplast genome was engineered first to confer herbicide, insect or disease resistance, drought or salt tolerance or phytoremediation. More recently, chloroplast genomes of major crops including cotton, wheat and soybean, vegetables, tubers, fruits and trees have been transformed. Significant advances have been made in expressing vaccine antigens against human bacterial, viral and protozoan pathogens in chloroplasts and animal studies demonstrated their efficacy against pathogen or toxin challenge. Most importantly, oral delivery of vaccine antigens bioencapsulated in plant cells was shown to be more efficacious than injectable vaccines or in developing oral tolerance against autoimmune disorders (diabetes, hemophilia). In the past few years, chloroplast genomes of >30 crops have been fully sequenced to further advance this technology. Chloroplast genome was modified to express industrial enzymes for biofuel production.  One of these enzymes, B-glucosidase, released active hormones from their inactive conjugates stored within chloroplasts and almost doubled plant biomass. Recent advances in this field will be presented.