Abstract: | The relationship between LOX (lipoxygenase) activity, SA (salicylic acid) and JA (jasmonic acid) accumulation was studied in the tobacco leaf under water stress. The result showed that LOX activity and JA content increased sirnutaneously with losing of water. NDGA(nordihydroguaiaretic), an inhibitor of LOX,inhibited simultaneously both the activity of LOX and the enhancement of JA level under the stress. Likewise,adding LOX to tobacco cell-free system led to the increase of JA content. It suggested that LOX could be a key enzyme in JA biosynthesis under water stress. SA inhibited the enhancement of JA level under the stress. |