Looking for classes? Ksquare Career Institute, Bengaluru →
Which one of the following generally acts as an antagonist to gibberellins?
A
IAA
B
Zeatin
C
Ethylene
D
ABA
Detailed Solution
Gibberellins are growth promoters: they break seed and bud dormancy, promote seed germination and stem elongation.
Abscisic acid (ABA) is a growth inhibitor: it induces seed and bud dormancy and inhibits seed germination and growth.
Since the effects of ABA are opposite to those of gibberellins, NCERT states that in most situations ABA acts as an antagonist to GAs.
IAA (an auxin) and zeatin (a cytokinin) are growth promoters, and ethylene is not the general antagonist of gibberellins.
Hence the antagonist to gibberellins is ABA.
Abscisic acid (ABA) is a growth inhibitor: it induces seed and bud dormancy and inhibits seed germination and growth.
Since the effects of ABA are opposite to those of gibberellins, NCERT states that in most situations ABA acts as an antagonist to GAs.
IAA (an auxin) and zeatin (a cytokinin) are growth promoters, and ethylene is not the general antagonist of gibberellins.
Hence the antagonist to gibberellins is ABA.