What is Sugiyama Medium? A Guide to Its Use in Plant Tissue Culture
Introduction
In the world of plant genetics and cell biology, plant tissue culture has emerged as a revolutionary technique that provides a controlled setting for the growth and multiplication of plants. One of the essential requirements for successful tissue culture is the use of appropriate growth media. Sugiyama Medium is one such media that has gained importance in plant tissue culture, especially in studying the Nicotiana tabacum (common tobacco) species. This medium supports callus formation, organ differentiation, and shoot generation, making it a valuable tool for scientists and researchers working in plant phylogenetics, transgenics, or propagation.
This post explores what Sugiyama Medium is, its uses in the field of plant tissue culture, and its typical composition.
What is Sugiyama Medium?
Sugiyama Medium was first formulated by Mitsuru Sugiyama in 1960 for the induction of plant organogenesis and is widely used for the cultivation of tobacco (Nicotiana tabacum) tissues. However, it has since been adapted for a variety of other plant species.
The medium is designed to promote both callus growth and shoot regeneration, two critical steps in plant tissue culture. Callus refers to masses of undifferentiated plant cells that can later differentiate into tissues like leaves, roots, or shoots when provided with the proper hormonal and nutritional signals. Shoot regeneration, on the other hand, is the crucial step where fully differentiated shoots can form from the callus. Sugiyama Medium is balanced in a way that facilitates both of these processes.
Specific Applications of Sugiyama Medium
- Callus Induction: Sugiyama Medium is effective in inducing callus tissues when explants (plant tissue samples) are subjected to the right plant growth regulators.
- Organogenesis: The medium is commonly used for the development and regeneration of organs such as shoots and roots from callus tissues.
- Genetic Engineering: Due to its versatility, this medium is often used in labs for genetic transformation protocols. Scientists can use Sugiyama Medium after introducing foreign genes into plant tissues to regenerate whole, transgenic plants.
- Propagation of Tobacco: Although developed for Nicotiana tabacum, Sugiyama Medium has also been utilized for other plant species, indicating its adaptability.
The Components of Sugiyama Medium
Like other plant tissue culture media, Sugiyama Medium contains several essential nutrients that provide the plant cells with the necessary ingredients for growth and differentiation. These nutrients can be broken down into macroelements, microelements, vitamins, a carbon source, solidifying agent (for agar), and plant growth regulators.
Here is a typical Sugiyama Medium formulation on a per liter basis:
Composition of Sugiyama Medium
| Component | Concentration (mg/L) |
|---|---|
| Macroelements | |
| – Potassium Nitrate (KNO₃) | 950 |
| – Ammonium Nitrate (NH₄NO₃) | 500 |
| – Calcium Chloride (CaCl₂·2H₂O) | 440 |
| – Magnesium Sulfate (MgSO₄·7H₂O) | 370 |
| – Potassium Phosphate (KH₂PO₄) | 170 |
| Microelements | |
| – Potassium Iodide (KI) | 0.83 |
| – Boric Acid (H₃BO₃) | 6.20 |
| – Manganese Sulfate (MnSO₄·H₂O) | 22.30 |
| – Zinc Sulfate (ZnSO₄·7H₂O) | 8.60 |
| – Sodium Molybdate (Na₂MoO₄·2H₂O) | 0.25 |
| – Ferrous Sulfate (FeSO₄·7H₂O) | 27.80 |
| – EDTA (Disodium Salt) | 37.30 |
| Vitamins | |
| – Thiamine-HCl (Vitamin B1) | 1.00 |
| – Pyridoxine-HCl (Vitamin B6) | 1.00 |
| – Nicotinic Acid | 1.00 |
| Carbohydrate Source | |
| – Sucrose | 30,000 |
| Plant Growth Regulators | |
| – Cytokinin (e.g., Kinetin) | 0.05 – 1.00 mg/L (Varies depending on the experimental design) |
| – Auxin (e.g., NAA or 2,4-D) | 0.01 – 1.00 mg/L (Varies depending on callus induction or organogenesis goals) |
| Solidifying Agent (if needed) | |
| – Agar* | 8,000 |
(⁕ Agar may be omitted if a liquid medium is used instead.)
pH Adjustment
The pH of Sugiyama Medium should typically be adjusted to 5.7 using either 1M NaOH (sodium hydroxide) or 1M HCl (hydrochloric acid) before autoclaving for sterilization purposes.
Practical Notes on Sugiyama Medium Usage
Autoclaving: Like most tissue culture media, Sugiyama Medium requires sterilization via autoclave (typically at 121°C for 20 minutes).
Customization: The amount of growth regulators, such as auxins (for callus induction) and cytokinins (for shoot regeneration), can be tweaked depending on the plant species and the specific type of tissue culture (e.g., direct vs. indirect organogenesis).
Alternative Solidifying Agents: While agar is the standard gelling agent used for solid Sugiyama Medium, researchers occasionally use other agents like phytagel to customize the rigidity of the medium, depending on the plant species.
- Storage: Once prepared, the medium can be stored in a cool and dark place for a short period; however, it is recommended to use fresh media for optimal results.
Conclusion
Sugiyama Medium has carved out a significant place in plant tissue culture—especially in studies involving tobacco (Nicotiana tabacum). Its balanced formulation offers a robust platform for inducing callus and promoting organogenesis, helping researchers explore genetic transformation, plant regeneration, and even large-scale plant propagation. Despite being originally designed for tobacco, the versatility of Sugiyama Medium makes it suitable for experiments involving various plant species.
If you’re venturing into experiments that require plant tissue culture, Sugiyama Medium can serve as an excellent base for consistent and reliable results.
References:
Sugiyama, M. (1960). Organogenesis in flowering plants. Publications related to plant culture and methodology.
Disclaimer: Always ensure to tailor the medium to your specific plant tissues and experimental needs. Procedures like adjusting plant growth regulators are often species-specific and can require preliminary trials.