title: Auxin as a positional signal in pattern formation in plants.
abstract: By using a novel, extremely sensitive and specific gas chromatography-mass spectrometry technique we demonstrate in Pinus sylvestris (L.) trees the existence of a steep radial concentration gradient of the endogenous auxin, indole-3-acetic acid, over the lateral meristem responsible for the bulk of plant secondary growth, the vascular cambium. This is the first evidence that plant morphogens, such as indole-3-acetic acid, occur in concentration gradients over developing tissues. This finding gives evidence for a regulatory system in plants based on positional signaling, similar to animal systems.
authors.affiliation: Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Uggla
authors.forename: T
authors.initials: T
authors.lastname: Moritz
authors.forename: G
authors.initials: G
authors.lastname: Sandberg
authors.forename: B
authors.initials: B
authors.lastname: Sundberg