In fall, however, cooler and shorter days trigger an end to auxin production, allowing the abscission layer to grow and cut off the circulation of water, nutrients and sugar to the leaves.

• 然而，在秋天，天气变冷、变短，这使得生长素停止生长，进而，隔离层自由生长，从而阻断了叶子的水、养料和糖的循环。