Occurrence of plant growth regulators in Psilotum nudum.

The endogenous content of the auxin indole-3-acetic acid (IAA), the cytokinins trans-zeatin (tZ), trans-zeatin riboside (tZR), dihydrozeatin (DHZ), dihydrozeatin riboside (DHZR), isopentenyladenine (iP) and isopentenyladenosine (iPR), the gibberellins GA(1), GA(3), GA(4), GA(7), GA(9) and GA(20) in the rhizome and aerial shoots during and after sporogenesis were measured by high-performance liquid chromatography-tandem mass spectrometry in the fern Psilotum nudum. The present study shows, for the first time, the presence of the auxin IAA, the cytokinins tZR, DHZR and iP, and the gibberellins GA(4), GA(9) and GA(20) in the rhizome and aerial shoots of this species and suggests a possible role of gibberellins in the evolution of ferns.