Triple Response of Ethylene
Ethylene is a phytohormone which is produced in the plant under the conditions of mechanical stress. Ethylene is a phytohormone which protects seedlings from getting damaged during germination.
Ethylene exhibits some influence on germinating seedlings. These responses are termed to be triple response.
*Elongation of internode is inhibited making the stems short.
*Increase in the thickness of the stem making the stem fat.
*Seedlings grow horizontally without responding to gravitropism giving rise to auxin imbalance. Ethylene removes this auxin imbalance and helps the seedling to grow properly.