Question

Which of the following hormones are responsible for shedding of leaves?
A. Abscisic acid
B. Gibberellin
C. Cytokinin
D. Auxin

Answer 1

Hint: These hormones are found in shoot and root tips and inspire cell separation, stem and root growth. They also can acutely have an effective plant orientation via supporting cell division to one facet of the plant in reaction to daylight and gravity.

Complete Answer:
To answer this question, first, we need to know about the plant hormones. Plant hormones have the maximum vital biochemicals affecting plant development and yield formation based on different conditions, involving stress. Plant hormones encompass auxin, abscisic acid, ethylene, gibberellins, cytokinins, salicylic acid, strigolactones, nitrous oxide and brassinosteroids. Plant functioning in stress condition is influenced by plant hormones that can assist the plant to tolerate the environmental stresses.

Now, let us find the solution from the option.
- ABA serves in various plant developmental systems, involving seed and bud inactivity, the maintaining of organ length and stomatal closure.
- Gibberellins (GAs) are plant hormones that modify diverse developmental processes, such as stem extension, germination, inactivity, blooming, flower growth, and leaves and fruits senescence.
- Cytokinins are a category of plant developmental elements (phytohormones) that encourage cell separation, or cytokinesis, within plant roots and shoots.
- Auxin and ethylene are plant hormones that play a major part in leaf abscission. High range of auxin triggers the formation of an extra of ethylene which ends up in leaf abscission.

Thus, the correct option is D. i.e. Auxin.

Note: Both herbal and synthetic auxins are utilized in horticulture, agriculture, domestic gardening, and plant science for the promotion of rooting, fruit setting, fruit thinning, and fruit-drop management. Other compounds that are just like auxin apply as selective weed killers and as retailers that exchange leaves from dicotyledonous plants (defoliating agents).