Title: | Phenotypic plasticity of cyanogenesis in lima bean Phaseolus lunatus-activity and activation of beta-glucosidase |
Author(s): | Ballhorn DJ; Heil M; Lieberei R; |
Address: | "Department of Botany, University of Duisburg-Essen, Universitatsstr. 5, 45117 Essen, Germany. daniel.ballhorn@uni-due.de" |
DOI: | 10.1007/s10886-005-9001-z |
ISSN/ISBN: | 0098-0331 (Print) 0098-0331 (Linking) |
Abstract: | "Cyanogenesis, the release of toxic HCN from damaged plant tissues, is generally considered as a constitutive plant defense. We found phenotypic plasticity of cyanogenesis in young leaves of lima bean Phaseolus lunatus based on increased activity of the beta-glucosidase in response to herbivore attack. Two aspects of plant cyanogenesis have to be considered in ecological analyses: (1) the cyanogenic potential (HCNp), which indicates the total amount of cyanide-containing compounds present in a given tissue, and (2) the cyanogenic capacity (HCNc), representing the release of HCN per unit time. This release is catalyzed by specific beta-glucosidases, whose activity is a crucial parameter determining overall toxicity. Enzymatic activity of beta-glucosidase-and, in consequence, the rate of HCN release-was increased significantly after 72 hr of incubation with spider mites as compared to non-infested leaves. Feeding by L1 larvae of Mexican bean beetles also led to enhanced enzymatic activity, whereas mechanical damage of leaf tissue had no effect on beta-glucosidase activity and the release of HCN. The results place plant cyanogenesis in the group of induced resistance traits, whose degree of activity depends on the feeding by a particular herbivore" |
Keywords: | Animals Coleoptera/physiology Female Genotype Host-Parasite Interactions Hydrogen Cyanide/analysis/*metabolism Phaseolus/*metabolism/parasitology Phenotype Pheromones/analysis/biosynthesis Plant Leaves/*metabolism/parasitology Tetranychidae/physiology bet; |
Notes: | "MedlineBallhorn, Daniel J Heil, Martin Lieberei, Reinhard eng 2006/03/17 J Chem Ecol. 2006 Feb; 32(2):261-75. doi: 10.1007/s10886-005-9001-z. Epub 2006 Mar 16" |