Question

Which one of the following generally acts as an antagonist to gibberellins?

• A. Ethylene
• B. Zeatin
• C. IAA
• D. ABA

Answer 1

The correct option is D

ABA

The correct option is D.
Explanation for correct option:

1. Abscisic Acid (ABA) is a plant stress hormone that plays a major role in drought signaling, germination, seed maturation, and seed dormancy.
2. A higher concentration of ABA leads to seed dormancy and promotes senescence whereas a higher concentration of GA promotes seed germination and delays senescence.
3. Hence, ABA is an antagonist to Gibberellins.

The explanation for incorrect options:

Option A

Ethylene is mainly involved in fruit ripening and triple response.

Option B35eb502df78a5481f

Zeatin, also known as cytokinin promotes cell division and delays senescence along with Gibberellins.

Option C

(IAA) is a plant hormone of class auxins and is involved in apical dominance and various responses against light and pathogens.

Final Answer: ABA is the plant hormone that acts as an antagonist to Gibberellins.