Abscisic acid promotes wilting of leaves but ethylene prevents wilting of leaves I think

Plant Hormones and Wilting of Leaves:

Plant hormones, also known as phytohormones, are chemical substances that regulate various physiological processes in plants. They play a crucial role in controlling growth, development, and responses to environmental stimuli. One of the plant hormones that prevent wilting of leaves is abscisic acid (ABA).

Abscisic Acid (ABA):
Abscisic acid is a plant hormone that is responsible for regulating several physiological processes, including seed dormancy, leaf senescence, and stress responses. It acts as a signal molecule that helps plants adapt to adverse environmental conditions, such as drought, salinity, and extreme temperatures.

Preventing Wilting:
Wilting of leaves occurs when there is a loss of turgidity, which is the result of excessive transpiration (loss of water through stomata) and insufficient water uptake by the roots. Abscisic acid plays a crucial role in preventing wilting by controlling stomatal closure and regulating water balance in plants.

Stomatal Closure:
Stomata are small openings present on the leaf surface that regulate the exchange of gases and transpiration. When water availability is limited, abscisic acid accumulates in the leaves, signaling the guard cells surrounding the stomata to close. This closure reduces transpiration, minimizing water loss and preventing wilting.

Regulating Water Balance:
Abscisic acid also helps regulate the water balance in plants by influencing the movement of water across cell membranes. It increases the permeability of cell membranes to water, allowing water to move out of cells in roots and into cells in leaves, thus maintaining proper hydration and preventing wilting.

Other Functions:
In addition to preventing wilting, abscisic acid also plays a role in other stress responses. It promotes the synthesis of proteins called late embryogenesis abundant (LEA) proteins, which protect cells from damage caused by dehydration and other stresses.

Conclusion:
Abscisic acid, a plant hormone, plays a crucial role in preventing wilting of leaves by regulating stomatal closure and water balance in plants. It acts as a signal molecule that helps plants adapt to adverse environmental conditions and ensures their survival in challenging situations. By understanding the role of abscisic acid and other plant hormones, scientists can develop strategies to improve crop tolerance to drought and other stresses.