Chemical composition of the exudate from excised maize roots

Summary The concentrations of inorganic ions in the exudate from excised roots of Zea mays have been measured for roots grown in both chloride and sulphate media. The results indicated that in roots exuded from sulphate media there was a significant inorganic anion deficit. Using the methods of thin layer chromatography and high voltage electrophoresis some organic constituents of the exudate have been identified. Exudate from sulphate-grown roots was found to contain 3 organic acids and a complex mixture of amino acids. Exudate from chloride-grown roots contained similar organic solutes, but at much lower concentrations than in the sulphate-grown root exudate.