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 HighWire Citing Articles via CrossRef Citing Articles via Web of Science (40) Citing Articles via Google Scholar Google Scholar Articles by Sitbon, F. Articles by Sandberg, G. Search for Related Content PubMed PubMed Citation Articles by Sitbon, F. Articles by Sandberg, G. Agricola Articles by Sitbon, F. Articles by Sandberg, G.

Development and Growth Regulation

Free and Conjugated Indoleacetic Acid (IAA) Contents in Transgenic Tobacco Plants Expressing the iaaM and iaaH IAA Biosynthesis Genes from Agrobacterium tumefaciens¹

Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-90183 Umeå, Sweden

The Agrobacterium tumefaciens T-DNA gene iaaM was introduced by leaf-disc transformation into transgenic tobacco (Nicotiana tabacum) plants expressing the iaaH gene. Regenerated calli were screened for the presence of indole-3-acetamide (IAM), by gas chromatography-multiple ion monitoring-mass spectrometry, and IAM-containing calli were further analyzed for free and conjugated indoleacetic acid (IAA). It was found that transgenic calli on average contained twice as much free IAA and three times more conjugated IAA than calli from wild-type plants. About 40% of the transformed calli could be regenerated to plants. The distribution of free and conjugated IAA was measured in transformed plants with a normal phenotype and compared with equivalent wild-type plants. The IAA content of transgenic plants was only slightly increased, whereas IAA-conjugate levels were enhanced significantly. These data suggest that conjugation of IAA may serve as a regulatory mechanism, contributing to maintenance of steady-state IAA pool sizes during tobacco growth and development.

This article has been cited by other articles:

				C. P. Keller, R. Stahlberg, L. S. Barkawi, and J. D. Cohen Long-Term Inhibition by Auxin of Leaf Blade Expansion in Bean and Arabidopsis Plant Physiology, March 1, 2004; 134(3): 1217 - 1226. [Abstract] [Full Text] [PDF]

				I. Barlier, M. Kowalczyk, A. Marchant, K. Ljung, R. Bhalerao, M. Bennett, G. Sandberg, and C. Bellini The SUR2 gene of Arabidopsis thaliana encodes the cytochrome P450 CYP83B1, a modulator of auxin homeostasis PNAS, December 19, 2000; 97(26): 14819 - 14824. [Abstract] [Full Text] [PDF]