Transgenic Plants for Molecular Forming - An additional major goal. of biotechnology industry is also the use of transgenic plants as 'factories' for manufacturing speciality chemicals and pharmaceuticals. Sugars, fatty acids, starches, celluloses, rubber and wax are traditionally obtained from plants and genetic engineering can be used to increase their production.
Following are some of the examples:
(1) Transfer of a gene for mannitol dehydrogenase from E. coli to tobacco was achieved, which led to increase in the level of mannitol in transgenic tobacco plants.

(2) Transfer of bacterial gene (from Klebsiella) for cyclodextrin glucosyltransferase (CGTase) to potato was achieved successfully, leading to the production of α- and β cyclodextrins (CDs) in potato tubers.

(iii) the CGTase structural gene from Klebsiella and
(iv) nopaline synthase (nos) 3' region.
More transgenic plants with CGTase gene may be produced in view of the present high cost and world demand of CDs and due to availability of a number of CGTase genes.

(3) Transfer of genes for acetoacetyl CoA reductase (phb B) and polyhydroxybutyrate (PHB) synthase (phb C), which catalyze two steps in the production of polyhydroxybutyrate or PHB (a biodegradable thermoplastic polymer).These genes were successfully transferred and their expression was demonstrated in transgenic plants of Arabidopsis thaliana.

(4) Chimeric genes having CaMV promoter and encoding human serum albumin (HSA) were transferred successfully and transgenic potato and tobacco plants obtained. The secretion of protein was achieved by using either the human preprosequence or the signal sequence from extracellular PR -S protein from tobacco. HSA was secreted in transgenic leaf tissue.

(5) The production of pharmaceutically active compounds like enkephalins was achieved in transgenic oil seed rape.