Phosphate absorption by soybean varieties: the influence of ferulic acid

Abstract

The effect of ferulic acid upon phosphate absorption by excised and intact roots of three soybean (Glycine max (L.) Merrill) varieties (Hill, Ogden, and Jackson) was examined using 32 P-labelled solutions. Kinetic analysis of the phosphate uptake rates of roots of 3-day-old seedlings showed that 0.5 and 1.0 mM ferulic acid inhibited the absorption of phosphate by each variety. This inhibition was noncompetitive; the presence of ferulic acid reduced the V max values of the absorption systems but did not alter the values of the apparent K m . No direct effect upon the translocation of absorbed phosphate was found in the intact seedlings.