Studies of signal transduction of salicylic acid in cucumber cells

For the first time, the signal transduction pathway of salicylic acid (SA) was investigated by using H-3-labelling, thin-layer chromatography and anion exchange column chromatography. It was found that SA stimulated the activity of membrane bound phospholipase C (PLC), accelerated the breakdown of phosphatidylinositol-4-monophosphate (PIP) and phosphatidylinositol-4,5-bisphosphate (PIP2) and increased the levels of inositol-1,4-bisphosphate (IP2),inositol-1, 4,5-trisphosphate (IP3) and diacylglycerol (DAG). These indicated that signal transduction of SA was probably accomplished through the mediation of phosphatidylinositide signal transduction system in cucumber ( Cucumis sativa L.).