Cytoplast Production Sequence Explained

The production of cytoplasts (protoplasts) and subsequent cybrid formation involves a specific, ordered sequence of steps to ensure successful isolation and manipulation of plant cells. The correct sequence ensures the integrity and viability of the protoplasts.

Key Steps in Cytoplast Production:

1. Osmotic Stabilizer Application: The process begins by placing plant cells in an osmotically balanced solution. This is crucial because the subsequent removal of the cell wall will expose the plasma membrane. Without a suitable osmotic stabilizer (like sorbitol or mannitol), the protoplasts would lyse due to water influx in a hypotonic environment.
2. Cell Wall Digestion: Once the cells are stabilized osmotically, enzymes like cellulases and pectinases are introduced. These enzymes break down the complex structure of the plant cell wall, releasing the cell membrane-bound protoplast.
3. Protoplast Viability Assessment: After enzymatic digestion and isolation, the viability of the resulting protoplasts must be confirmed. This is often done using staining methods (e.g., fluorescein diacetate staining) to determine which protoplasts are alive and capable of further manipulation, like fusion.
4. Cybrid Formation: Finally, viable protoplasts are induced to fuse, forming cybrids (cytoplasmic hybrids). This fusion can be achieved through chemical agents (like PEG) or electrofusion, allowing for the combination of cytoplasmic components, potentially leading to novel genetic combinations or specific research outcomes.

Therefore, the correct sequence is: Osmotic stabilizer $\rightarrow$ digestion of cell wall $\rightarrow$ protoplast viability $\rightarrow$ cybrid formation.