Question

Which are widely used techniques to fuse plant protoplasts?
A. Chemical fusion by PEG
B. Electric stimulation
C. High $Ca^{2+}$ -high pH method
D. Particle gun method
Choose the correct answer from the options given below:

• A. A, C and D only
• B. B, A and C only
• C. A, B and D only
• D. B, C and D only

Hint:

Fusion techniques are about bringing membranes together. Remember: PEG (Glue), Electricity (Zapping), and Calcium/pH (Charge neutralizing).

Answer 1

The Correct Option is B

Concept: Protoplast fusion (somatic hybridization) requires overcoming the natural negative charge on the surface of the plasma membrane so that two different cells can come into contact and merge.

Step 1: Chemical Methods (A and C).
Polyethylene glycol (PEG) (A) is the most common chemical fusogen; it acts as a molecular bridge that causes protoplasts to adhere and fuse. The High $Ca^{2+}$ - high pH method (C) works by neutralizing the surface charges and inducing membrane disturbances that facilitate fusion.

Step 2: Physical Methods (B).
Electric stimulation (B) (Electrofusion) uses short, high-voltage pulses to create temporary pores in the membranes (electroporation). When two protoplasts are aligned in an electric field, these pores allow their intensive contents to merge.

Step 3: Identifying the Outlier.
The Particle gun method (D) (Biolistics) is a technique for *genetic transformation* (delivering DNA into cells), not for fusing two whole cells together.