ABA is a derivative of

The correct answer is Carotenoids

Concept:

• Abscisic acid (ABA) is a plant hormone that plays an important role in regulating plant growth, development, and stress responses. It is particularly known for its role in seed dormancy and response to environmental stresses such as drought.
• ABA is synthesized in the plastids of plant cells from carotenoids, which are pigments that also contribute to photosynthesis and photoprotection.

Explanation:

• Carotenoids: These are organic pigments found in the chloroplasts and chromoplasts of plants and some other photosynthetic organisms. ABA is derived from carotenoids, specifically through the oxidative cleavage of carotenoids such as violaxanthin and neoxanthin.
• Adenine: This is a nucleobase (a purine derivative) used in the formation of nucleotides of DNA and RNA. It is not related to the synthesis of ABA.
• IAA (Indole-3-Acetic Acid): This is a major plant hormone known as auxin, which is involved in cell elongation, root growth, and other growth processes. It is not a precursor or derivative of ABA.
• ABA: This is the hormone in question and not its precursor. The question is specifically about the derivative or precursor of ABA.