ABSTRACT
Modem biotechnology has evolved from genetic engineering to introduce single gene traits to metabolic engineering to manipulate multigenic traits, thereby coding for complete metabolic pathways, bacterial operons, or therapeutic molecules that require an assembly o f complex multi-subunit proteins. Mastering metabolic engineering for directed improvement o f biological cell factories by manipulating enzymatic, transport and regulatory functions with the use o f r-DNA technology is the essence and hallmark o f the production o f recombinant proteins for human therapy, popularly known as biopharmaceuticals. Metabolic engineering in plants is currendy at the threshold o f an exciting new paradigm which emphasizes the introduction o f traits that need manipulation o f metabolic pathways or coordinated expression o f multi-subunit proteins. Orchestrating the various ways o f controlling gene expression in transgenic plants and o f the numerous techniques o f developing a better understanding o f the fundamental physiology o f the process, the expression level, timing, subcellular location, and tissue or organ specificity is what makes metabolic engineering in plants so challenging and exciting. It promises to create new opportunities in custom designing and delivering novel molecules for therapeutic and biomedical applications. Thus, this chapter focuses on the tremendous potential o f plants as cost-effective and sustainable multi-gene expression platform and transgenic manufacturing systems and discusses both the current status and role o f functional genomics and metabolic engineering in the targeted improvement o f cellular activities for the large-scale production o f biopharmaceuticals.
