Functional diversifications of cyanogenic glucosides

Cyanogenic glucosides are present in many plants and their ability to liberate toxic HCN offers an immediate chemical defense response to herbivores and pathogens causing damage of the plant tissue. Countermeasures have evolved to overcome this type of defense and in some cases herbivores and pathogens are able to exploit the presence of cyanogenic glucosides to their own advantage. In plants, cyanogenic glucosides have gained additional functionalities as transporters of nitrogen and operation of an endogenous turnover pathway may enable plants to withdraw the nitrogen and glucose deposited in cyanogenic glucosides for use in primary metabolism. The aim of this review is to provide an overview of the new knowledge on these diverse functionalities of cyanogenic glucosides.