Question

Which is a stress hormone?

Options

• Benzyl aminopurine

• DAA

• Ethylene

• Abscisic acid

Answer 1

Abscisic acid

Explanation:

Abscisic acid (ABA) is known as the plant stress hormone because its synthesis is rapidly triggered by adverse environmental conditions like drought, high salinity, and extreme temperatures. It helps the plant survive these conditions by stimulating the immediate closure of stomata to prevent excessive water loss through transpiration. Additionally, it promotes seed and bud dormancy, allowing the plant to suspend growth and withstand harsh conditions until favourable environments return.