PLANT HORMONE RECEPTORS - COMPARISON OF NAPTHALENEACETIC ACID BINDING BY MAIZE EXTRACTS AND BY A NON-PLANT PROTEIN

The binding of napthaleneacetic acid (NAA) by the animal protein bovine serum albumin has been studied and compared with the properties of NAA binding by maize extracts. In both systems binding is optimal at an acid pH, it is reversible, saturable and the equilibrium is rapidly established. The ability of a number of auxins, anti-auxins and structurally-related compounds to compete with NAA binding in the two systems have been compared. The results indicate that in assessing whether a plant protein capable of binding auxins is involved in a hormonal response, the ability to bind auxins in a specific and competitive manner should be interpreted with caution. © 1979.