The role of stelar auxin in the development of the primary root of Zea mays.

Neither the removal of the stele, which contains over 90% of the auxin found in the primary roots of Zea mays L., nor its replacement by auxin (indole-3-acetic acid, IAA) solutions had any demonstrable effect on the elongation of root tips or subapical cortical cylinders (except inhibition at higher IAA concentrations). Other possible developmental roles for stelar auxin in roots are discussed.