Constitutive polymorphic cyanogenesis in the Australian
rainforest tree, Ryparosa
Bruce L. Webber, Rebecca E. Miller, Ian E. Woodrow
School of Botany, The University of Melbourne, Victoria 3010, Australia
Phytochemistry 68 (2007) 2068–2074
Cyanogenesis, the liberation of volatile hydrogen cyanide from endogenous
cyanide-containing compounds, is a proven plant defence mechanism
and the particular cyanogens involved have taxonomic utility. The cyclopentenoncyanhydrin
glycoside gynocardin was the only cyanogen isolated from foliar
tissue of the rare Australian rainforest tree, Ryparosa kurrangii (Achariaceae).
Mechanical damage simulating foliar herbivory did not induce
a significant increase in the expression of cyanogenesis over a 24
h period, indicating cyanogenic herbivore defence in R.
kurrangii is constitutive. The cyanogenic potential
of mature leaves was quantitatively polymorphic between trees
in a natural population, ranging from 0.54 to 4.77 mg CN /g dry wt
©2007 Elsevier Ltd. All rights reserved.