Question

Leaf abscission is promoted by

• A. Ethylene
• B. Abscisic acid
• C. Cytokinin
• D. Tryptophan

Answer 1

The correct option is A Ethylene

Leaf abscission is a detachment or fall of older leaves.It occurs at the base of the petiole. During abscission, high synthesize of ethylene is observed along with decrease in the concentration of auxin. Ethylene synthesizes enzymes like cellulase and pectinase which are involved in cell wall degradation. These enzymes loosens the cell wall and cells separate which ultimately leads to leaf abscission.

Thus, the correct answer is option A.