Question

Which of the following enhances or induces fusion of protoplasts?
A. IAA and kinetin
B. IAA and gibberellins
C. Sodium chloride and potassium chloride
D. Polyethylene glycol and sodium nitrate

Answer 1

Hint: Somatic fusion also called protoplast fusion, is a genetic modification in plants in which two distinct species of plants are fused together to form a new hybrid plant which has the characteristics feature of both.

Complete step by step answer:
IAA is the main auxin in plants, regulating growth and developmental processes such as cell division and elongation, tissue differentiation, apical dominance, and responses to light, gravity, and pathogens. Kinetin is a cytokinin. Cytokinins are compounds that stimulate plants to grow.
-Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. -Sodium chloride also increases the level of sucrose in storage roots and allows beet plants to withstand water stress more readily, possibly by increased turgor pressure. -Plants that are exposed to too much salt can become sick and even die, as seen in areas where salt treatments on snow kill plants. Potassium chloride has the same water softening effects and is actually good for plants as the largest chemical source of potassium. -It was assumed that polyethylene glycol (PEG) of large molecular weight did not penetrate the plant and thus was an ideal osmoticum for use in hydroponics root medium. -Sodium nitrate provides an immediately available source of nitrogen nutrition to plants since it is highly soluble.
-Protoplast fusion is the most important tool in plant breeding because it has the potential to create “cybrids” it is a new method for hybridizing these cybrids containing organelles from both parents and increases its efficiency and genetic variability. Polyethylene glycol and sodium nitrate enhance its fusion; because the presence of Na+ ion induces localized realignment of the lipoprotein in the membrane which in turn allows fusion. Whereas PEG solutions induce tight adhesion of protoplasts owing to electrostatic forces.
So, here the correct answer is Option D that is polyethylene glycol and sodium nitrate.

Note: Protoplasts can be obtained by stripping the cell wall from the plant, bacteria, or fungal cells by mechanical, chemical, or enzymatic method. The fusion of two protoplasm results in the formation of cybrids.