Undestructive Measurement of Acid Phosphatase Activity in the Root of Rice Seedlings

Abstract

Conditions for undestructive assay system of acid phosphatase in the intact roots of rice ( Oryza sativa L.) seedlings as a marker of physiological activity of roots using p-nitrophenyl phosphate as a substrate were investigated Phosphatase activity was linear up to 3h at the concentrations from 0.5 to 10mM. Optimum acid phosphatase activity was obtained between pH 3 and 6 at 25-30°C. The enzyme activity of the whole roots including seminal and crown ones at the 4th leaf stage plant was higher than that at younger or older seedling stage. Using this method, we also investigated the effect of isoprothiolane (IPT), which is known as a plant growth regulator, on acid phosphatase activity in roots of rice seedlings. This compound promoted acid phosphatase activity in rice roots.