Biotechnology plays a significant role in the production of secondary metabolites in plants by using advanced techniques to enhance, regulate, and scale up their synthesis under controlled conditions. Secondary metabolites are organic compounds such as alkaloids, flavonoids, terpenoids, phenolics, and glycosides, which are not directly involved in plant growth but have important pharmaceutical, agricultural, and industrial uses.
Here’s how biotechnology helps in their production:
- Plant Tissue Culture Techniques
- Biotechnology uses callus and cell suspension cultures to produce secondary metabolites in vitro (outside the plant).
- Cells or tissues are grown under sterile and controlled conditions, allowing continuous metabolite production without depending on whole plants.
- For example, shikonin, an important dye and medicinal compound, is produced using cell culture of Lithospermum erythrorhizon.
- Elicitor Treatment
- Elicitors (biotic or abiotic agents) such as methyl jasmonate, salicylic acid, or fungal extracts are used to stimulate the production of secondary metabolites.
- They mimic stress conditions, triggering the plant’s defense responses that lead to enhanced metabolite synthesis.
- Genetic Engineering
- Specific genes responsible for secondary metabolite biosynthesis can be identified, isolated, and inserted into plants or microbial hosts to increase yield.
- For example, overexpression of genes involved in alkaloid biosynthesis can boost production in medicinal plants.
- Metabolic Engineering
- This approach modifies the metabolic pathways within plant cells to direct more precursors toward desired secondary metabolites.
- Enzyme-coding genes are upregulated, and competing pathways can be suppressed to increase efficiency.
- Hairy Root Culture using Agrobacterium rhizogenes
- Infection by Agrobacterium rhizogenes induces the formation of hairy roots, which are genetically stable and grow rapidly in culture.
- These roots are excellent producers of secondary metabolites such as tropane alkaloids and ginsenosides.
- Bioreactor Technology
- Large-scale production is achieved using bioreactors, where plant cells, tissues, or hairy roots are grown in controlled environments.
- This allows continuous, high-yield production of valuable metabolites for pharmaceuticals and cosmetics.
- Synthetic Biology Approaches
- Scientists use synthetic biology to reconstruct plant metabolic pathways in microbial systems (like yeast or bacteria), enabling faster and cheaper production of plant-based compounds.
In summary, biotechnology helps in enhancing yield, reducing production time, and ensuring sustainability in the production of secondary metabolites. It allows large-scale production of compounds that would otherwise be limited by slow plant growth or low natural yield.