Cyanogenic glucosides are chemical defense compounds found in a large number of plant species. They protect the plant against herbivores as leaf damage will result in the release of toxic hydrogen cyanide gas. The presence of cyanogenic glucosides is a problem in various crops of social and economical importance such as cassava, sorghum, barley, almonds, and forage legumes such as clover. Cyanogenic glucosides are a major research topic in the Plant Biochemistry Laboratory and our group contributes with a molecular genetics approach to the overall research program.
We have generated a large mutant collection of cyanogenesis deficient mutants in the legume Lotus japonicus (Takos et al., 2010, Plant Cell 22:1605). This has revealed diversification in cyanogenic glucoside metabolism as well as identified novel genetic loci. We study differences in substrate specificity and gene expression patterns of enzymes in the cyanogenic pathway, e.g. β-glucosidases, to understand their distinct biological roles. In addition to the mutant collection we make use of reverse genetics and genetic variation in natural accessions of Lotus. Novel genetic loci are being identified by map-based cloning.