Transport de l'auxine-14C en provenance de jeunes gousses de Vicia faba L.

Summary After the injection of ¹⁴C]indole acetic acid (IAA) into very young pods of broad-bean (Vicia faba L.) the movement of the ¹⁴C in the peduncle and stem was followed by autoradiography. In samples with only one young pod the basipetal transport was always clearly dominant. Most of the radioactivity was found in the bundles, particularly in the outer region of the bundle and also in the inner region (protoxylem parenchyma). The progression of the tracer was relatively complex. The rate of movement of the radioactive «front» could be as much as 2 cm·h^-1 but most of the ¹⁴C moved towards the base at rates clearly less than that of the «front». Chromatograms with several solvent systems showed that IAA was the main or the only mobile radioactive substance. During transport, a part of IAA was converted into indole-3-aldehyde (IAld) and indole-3-acetyl-aspartic acid (IAAsp). IAAsp and possibly also IAld, which were found mainly near the donor pod, seemed immobile. This work is part of a study on the interchange of phytohormones between fruit and plant.

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Abréviations AIA acide indolyl-acétique - AIAsp acide indolyl-acetyl-aspartique - IAld indolyl-aldéhyde