In plant biotechnology, a suspension typically refers to a plant cell culture maintained in a liquid medium.
A plant cell suspension is a culture developed by transferring the relatively friable portion of the callus into a liquid medium. It is maintained under suitable conditions of aeration, agitation, light, temperature, and other physical parameters. In a plant cell suspension, the cells divide, multiply and grow.
Understanding Plant Cell Suspension Cultures
Plant cell suspension culture is a fundamental technique used in plant biotechnology and tissue culture laboratories. Unlike solid callus cultures, where cells form an undifferentiated mass on agar, suspension cultures involve single cells or small cell aggregates dispersed throughout a liquid growth medium.
How is a Suspension Culture Initiated?
The process usually begins by selecting friable (easily crumbled) callus tissue. This selected callus is then transferred into a liquid medium within a flask or bioreactor.
Key Maintenance Factors
Maintaining a healthy suspension culture requires careful control of several environmental factors:
- Aeration: Providing adequate oxygen to the cells.
- Agitation: Continuous shaking or stirring to keep cells dispersed, prevent clumping, and improve nutrient/oxygen distribution.
- Light: Specific light conditions may be required depending on the plant species and cell type.
- Temperature: Maintaining an optimal temperature range for cell growth.
- Nutrients: The liquid medium contains essential nutrients, hormones, and vitamins necessary for cell division and growth.
Why Use Suspension Cultures?
Suspension cultures offer several advantages over solid cultures:
- They facilitate rapid cell division and multiplication, leading to a high yield of cells.
- They are ideal for studying cellular processes, such as metabolism and gene expression, as cells are more uniformly exposed to the medium.
- They are scalable and can be used for large-scale production of valuable secondary metabolites or biomass in bioreactors.
- They provide a convenient source of uniform cells for genetic transformation experiments.
In summary, a plant cell suspension is a dynamic liquid culture system where dispersed plant cells actively grow and divide under controlled environmental conditions, initiated from friable callus tissue.
