Question

Mention the correct sequence of events for the isolation of protoplasts from embryogenic suspension cultures of rice.
A. Excise yellow/white compact and nodular embryogenic callus
B. Staining with fluorescein diacetate
C. Filter the cell suspension through a nylon sieve
D. Filter the protoplast suspension through sieves
Choose the correct answer from the options given below:

• A. A, B, D, C
• B. A, C, D, B
• C. C, B, A, D
• D. C, D, B, A

Hint:

The logical flow is: Pick the tissue (A) $\rightarrow$ Clean the clumps (C) $\rightarrow$ Filter the product (D) $\rightarrow$ Check if they are alive (B).

Answer 1

The Correct Option is B

Concept: Isolating protoplasts from rice requires a specific workflow to ensure the cells are healthy and free from debris. This starts with the tissue source and ends with quality control.

Step 1: Source Selection (A).
The first step is selecting the best tissue. For rice, this involves the Excision of yellow/white compact and nodular embryogenic callus (A), which provides the most active and uniform cells for isolation.

Step 2: Suspension and Cleaning (C).
Once the callus is placed in a liquid medium to create a suspension, the mixture must be cleaned. Filtering the cell suspension through a nylon sieve (C) removes large clumps and debris, leaving a fine population of cells ready for enzyme digestion.

Step 3: Protoplast Collection and Viability (D and B).
After enzymatic digestion (not listed as a separate letter here), the resulting protoplast suspension is filtered through sieves (D) to separate the naked protoplasts from undigested cells and walls. Finally, the quality of the isolated cells is checked by Staining with fluorescein diacetate (B) to confirm they are alive and viable.