Medicinal plants are the most important source of life saving drugs for the majority of the world`s population. Plant secondary metabolites are the economically important as drug, fragrances, pigments, food additives and pesticides. The biotechnological tools are important to select, multiply, improve and analyze medicinal plants. Plant cell culture systems represent a potential renewable source of valuable medicinal compounds, flavours, fragrances and colorants, which cannot be produced by microbial cells or chemical synthesis. In-vitro production of secondary metabolites in plant cell suspension culture has been reported from various medicinal plants and bioreactors are the key step towards commercial production of secondary metabolites by plant biotechnology. Genetic transformation is a powerful tool for enhancing the productivity of novel secondary metabolites; especially by Agrobacterium tumefacians. Combinatorial biosynthesis is another approach in the generation of novel natural products and for the production of rare and expensive natural products. DNA profiling techniques like DNA microarrays save as suitable high throughput tools for the simultaneous analysis of multiple genes and analysis of gen expression that becomes necessary for providing clues about regulatory mechanism, biochemical pathways and broader cellular functions.
