Question

Universally required vitamin in tissue culture medium is

• A. Nicotinic acid
• B. Glutamic Acid
• C. Thiamine HCl
• D. Sucrose

Hint:

Thiamine (Vitamin B1) is the only vitamin that is absolutely required across almost all plant tissue culture media formulations, including MS, B5, and Linsmaier-Skoog media.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Plant tissue culture media require specific inorganic salts, carbon sources, plant growth regulators, and vitamins to support the growth and development of plant cells in vitro.
While plant cells can synthesize vitamins in vivo, their biosynthetic capacity is often limited under in vitro conditions, making the addition of exogenous vitamins essential.

Step 2: Detailed Explanation:
Among the various vitamins used in plant tissue culture formulations, Thiamine HCl (Vitamin B1) is considered universally required.
Thiamine acts as an essential cofactor in its active form, thiamine pyrophosphate (TPP), which is required by enzymes such as pyruvate dehydrogenase and transketolase.
These enzymes are central to carbohydrate metabolism, the citric acid cycle, and the pentose phosphate pathway.
Without an exogenous supply of Thiamine HCl, cultured plant cells cannot sustain cell division and growth, leading to tissue chlorosis and death.
Nicotinic acid (A) is beneficial and frequently added to formulations like the Murashige and Skoog (MS) medium, but it is not universally mandatory for all plant species.
Glutamic acid (B) is an amino acid rather than a vitamin, and sucrose (D) serves as the primary carbon and energy source rather than a vitamin.
Therefore, Thiamine HCl is the only universally required vitamin in plant tissue culture media formulations.

Step 3: Final Answer:
The correct vitamin is Thiamine HCl, which corresponds to option (C).