BIOMOLECULES AND ENZYMES

Detailed explanation-1: -So, the correct answer is ‘Abscisic acid’.

Detailed explanation-2: -Abscisic acid (ABA) is an important phytohormone regulating plant growth, development, and stress responses.

Detailed explanation-3: -Abscisic acid causes abscission, i.e., falling of leaves and fruits from the plant body.

Detailed explanation-4: -Abscisic acid (ABA) has been shown to promote arbuscule formation in tomato (Solanum lycopersicum). Here, we show that ABA modulates the establishment of the AM symbiosis in Medicago truncatula by promoting fungal colonization at low concentrations and impairing it at high concentrations.

Detailed explanation-5: -Abscisic acid (ABA) is a general plant-growth inhibitor. It induces dormancy and prevents seeds from germinating; causes abscission of leaves, fruits, and flowers; and causes stomata to close.