It showed that paclobutrazol decreased the polyamines in young leaves, but increased the polyamines in matrured leaves and delayed senescence at the same time.

• 结果证明多效唑对内源多胺的影响较复杂，多效唑降低了幼嫩叶片的多胺含量，却提高了成熟叶片衰老阶段的多胺含量，并起到延缓衰老的作用。