ऊती संवर्धन पद्धतीत अल्पांश प्रमाणात लागणारे व पेशींतील विकर सिस्टमला उत्प्रेरित करणारे पदार्थ _____ होत.

The correct answer is Option C (vitamins).

Key Points:
• Tissue Culture Nutrient Media Composition (e.g., MS Medium):
• Plant cell media require inorganic macro/micronutrients, carbon sources, and organic supplements.
• Functional Role of Vitamins:
• Vitamins (such as Thiamine / Vitamin B1, Pyridoxine / B6, Nicotinic acid, and Inositol) are required in very minute (trace) quantities.
• They function as essential organic cofactors and coenzymes that activate and catalyse key cellular enzyme systems involved in cellular metabolism and differentiation.
• In contrast, sucrose serves as the bulk carbon/energy source (2-4%), amino acids supply nitrogen building blocks, and agar serves as a structural gelling substrate.
• Therefore, compounds needed in trace amounts to catalyse enzymes are vitamins (Option 3).
• Key Takeaway: Vitamins in plant tissue culture media function as essential cofactors needed in trace amounts to activate cellular enzyme systems.