Protoplast

A protoplast is a biological cell whose rigid cell wall has been partially or completely removed, allowing for manipulation and study of the cell's internal components, including the plasma membrane, cytoplasm, and nucleus (in eukaryotic cells). This process can be achieved enzymatically using cell wall-degrading enzymes (like cellulase and pectinase in plant cells) or mechanically. Protoplasts are typically spherical and osmotically sensitive, requiring careful handling in isotonic solutions to prevent bursting or shrinking. They are valuable tools in various fields, including plant biotechnology for genetic modification, somatic hybridization (fusing two protoplasts), and studying cell wall synthesis and membrane function. The removal of the cell wall allows for easier uptake of foreign DNA or other substances, making protoplasts ideal for genetic transformation experiments. Careful attention to culture conditions, including osmotic support and nutrient supply, is essential for protoplast survival, regeneration, and proliferation. These cells act as crucial study subjects for the interaction between cells and other molecules.

Protoplast meaning with examples

• Plant scientists used protoplasts of tobacco cells to successfully introduce a gene for herbicide resistance. These isolated cells, lacking their cell walls, readily took up the foreign DNA, allowing for efficient genetic transformation and producing herbicide-resistant tobacco plants. The protoplasts provided an efficient pathway for genetic modification research.
• Researchers utilized protoplasts from different species of potatoes to facilitate somatic hybridization experiments, resulting in hybrid plants with desired traits. The absence of the cell wall allowed for direct fusion, bypassing sexual reproduction. This offered an alternative path to breeding, giving desirable qualities.
• In cell biology studies, scientists employed protoplasts to investigate membrane transport mechanisms by introducing fluorescently labeled molecules. The protoplasts were easily studied under a microscope without the interference of the cell wall. This helped them observe cellular uptake.
• During protoplast culture, specific osmotic stabilizers, such as mannitol, were added to prevent bursting, and nutrients were provided to promote regeneration. These techniques provided the optimal environment. The protoplasts demonstrated their value as an adaptable subject.
• By exposing protoplasts to specific cell wall synthesis inhibitors, researchers could observe the effects on the re-formation of the cell wall. The absence of the cell wall made it easier to monitor how it was built from scratch. This allowed a new view.