This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Wochok, Z. S. Articles by Sussex, I. M. Search for Related Content PubMed PubMed Citation Articles by Wochok, Z. S. Articles by Sussex, I. M. Agricola Articles by Wochok, Z. S. Articles by Sussex, I. M.

Articles

Morphogenesis in Selaginella

II. Auxin Transport in the Root (Rhizophore) ¹

I. M. Sussex^b

^a Department of Biology, University of Alabama, University, Alabama 35486, Department of Biology, Yale University, New Haven, Connecticut 06520

The rhizophore of Selaginella willdenovii Baker develops from the ventral angle meristem. The morphological nature of this organ has been in dispute. The purpose of this investigation was to obtain physiological evidence to support the contention that the rhizophore is a root and not a shoot. This was accomplished by studying the movement of ³H-indoleacetic acid and ¹⁴C-indoleacetic acid in Selaginella rhizophores. In 6-millimeter tissue segments, twice as much radioactivity accumulated in acropetal receivers as in basipetal. During 1 hour of transport in intact roots auxin traveled twice as far in the acropetal direction as basipetal. A significant amount of radioactivity transported in the tissue was found to co-chromatograph with cold indoleacetic acid. Decarboxylation accounted for 10% loss of activity from donors. The data provide sufficient physiological evidence that this organ is morphogenetically a root.