Question

The term synergistic action of hormones refers to the situation of:
1. When two hormones act together but bring about opposite effects.
2. When two hormones act together and contribute to the same function.
3. When many hormones bring about any one function.
4. When one hormone affects more than one function.

Answer 1

Correct Answer - Option 2 : When two hormones act together and contribute to the same function.

Concept-

• A plant hormone or phytohormone is a chemical substance produced naturally in plants that are translocated to another region for regulating one or more physiological reactions when present in low concentration.
• While all hormones are plant growth regulators, all plant growth regulators are not hormones.
• It divided into two groups-
  • Plant growth promoter- Auxins, Gibberellins, and cytokinins.
  • Plant growth inhibitor- Abscisic acid and ethylene.

Explanation-

• Synergistic action of hormones means when two hormones act together to produce the same effect with better results.
• For example, auxin, and cytokinin act synergistically for callus formation during tissue culture. Then callus gives rise to the new plant. Auxin helps in root formation and cytokinins help in shoot formation.

 

• The increase in auxin concentration with regard to cytokinin will promote root formation. Similarly increase in cytokinin with regard to auxin will promote shoot formation. So auxin suppresses the effect of cytokinin and cytokinin suppresses the effect of auxin. This is often referred to as the antagonistic effect of auxin and cytokinin.