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 PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Auer, C. A. Articles by Cooke, T. J. Search for Related Content PubMed PubMed Citation Articles by Auer, C. A. Articles by Cooke, T. J. Agricola Articles by Auer, C. A. Articles by Cooke, T. J.

Development and Growth Regulation

Comparison of Benzyl Adenine Metabolism in Two Petunia hybrida Lines Differing in Shoot Organogenesis ¹

Department of Botany, University of Maryland, College Park, Maryland 20742, Plant Hormone Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705, Laboratoire de Biologie Cellulaire, Institut National de la Recherche Agronomique, Route de Saint-Cyr, F 78026 Versailles Cedex France

The uptake and metabolism of the cytokinin benzyl adenine (BA) was compared in two lines of Petunia hybrida Vilm. differing in their shoot organogenic response. Leaf transfer experiments using shoot induction medium containing 4.4 micromolar BA showed that leaf explants from petunia line St40 required a shoot induction period of 6 to 10 days for commitment to shoot organogenesis; whereas leaf explants from petunia TLV1 required 12 to 28 days. The short induction period of petunia St40 and the higher organogenic response was positively associated with a threefold higher absorption of BA from the medium, an increased BA ribotide metabolite pool, the presence of BA within the explant during the shoot induction period, and the production of an unidentified metabolite C. However, the study of petunia TLV1 leaf explants showed that neither BA nor metabolite C are required during the shoot induction period for eventual shoot development. The longer shoot induction period of TLV1 was associated with low BA uptake during 24 days, a decreasing ribotide metabolite pool, the absence of benzyl adenosine triphosphate and metabolite C throughout the study, and the absence of BA within the explant during the shoot induction period. Differences in the shoot organogenic response of these related plant lines have been shown to be associated with differences in exogenous cytokinin uptake and the subsequent metabolism of that hormone.