Figure 3.

Comparison of the induction of MBPK activity and of inhibitor I protein by systemin in leaves of excised 14-day-old tomato plants. Plants were supplied with systemin in 10 mM phosphate buffer (pH 6.5) or buffer alone. At 30 min, leaves were assayed for MBPK activity (○) and at 24 hr leave juice was assayed for inhibitor I protein accumulation (•). The kinase activities are expressed as the fold activation above or below the level of the buffer control, which was assigned a value of 1.