Characterization of Multiple Acid Phosphatases in Salt-Stressed Spinach Leaves

Abstract

Incremental salt stress brought about a clear enhancement of the activity of acid phosphatases in hydroponically grown spinach (Spinacia oleracea L.) leaves. Sephacryl S-200 chromatography of the enzyme fraction revealed multiple forms of acid phosphatases of high (300 000), intermediate (100 000), and low (35 000) molecular weight in control and salt-stressed spinach leaves. A similar zymogram of acid phosphatases, showing at least six bands in polyacrylamide disc gel electrophoresis, was observed for control and stressed leaves. However, promotive effects of incremental salt stress on the activity of acid phosphatases were more pronounced in high molecular weight acid phosphatases. Substrate specificity and differential effects of some ions on the multiple acid phosphatases were also examined for control and salt-stressed leaves.