CHRISTIANSON, MICHAEL L.* AND STEPHEN H. DUFFY. Division of Biological Sciences, University of Kansas, Lawrence KS 66045. - Salicylate-regulation of development in the moss, Funaria hygrometrica.
While the canonical plant hormones, auxin, cytokinin, abscisic acid,
gibberellic acid, and ethylene, were originally isolated and described
in vascular plants, each has also been shown to be able to regulate
one or more aspects of growth and development in mosses. Since mosses
are the sister clade to the vascular plants, this common set of
hormones is hardly surprising. There are now some additional growth
regulators discovered in vascular plants, jasmonates, salicylates,
brassinolides, as well as oligosaccharins and even peptide homones,
and it is not known if these molecules are also ancestral regulators
or represent physiological innovations unique to the vascular plants.
Using the classic bioassay system, bud-formation in the moss
Funaria, our experiments find that exposure to salicylates
produces dose-dependent inhibition of bud formation, with half-maximal
inhibition at micromolar concentrations. Characterization of the time
at which salicylates affect bud formation and the kinetics of the
interaction with cytokinin concentration show the inhibition is not a
direct antagonism of cytokinin. While these experiments do not show
that mosses regularly use salicylates to regulate growth and
development, they confirm the presence of a salicylate signal
perception-transduction pathway in mosses and suggest its presence in
the common ancestor of mosses and vascular plants. Research support,
KU Undergraduate Biology Research Fund, NSF OSB-9550487.
Key words: bud-formation, development, Funaria hygrometrica, moss, salicylate