Plant are exposed to many stresses, not least of them
consumption by herbivores. As a result plants have evolved a diverse set of
chemical defensive chemicals, among them the glucosinolates-myrosenase system,
a.k.a. the Mustard Oil Bomb. This system is based on two separate components – glucosinolates,
organic compounds derived from glucose and an amino acid and an enzyme –
myrosinase, that degrade these compounds to obnoxious products.
Fleshy, ripe fruits facilitate seed dispersal by
attracting animals that consume the fruits and disperse the seeds.
Nevertheless, such fruits are likely to attract also seed predators, especially
given the high nutritional value of the seeds. Consequently, many fruits
contain secondary compounds in concentrations that deter potential consumers. Such
compounds are effective against seed predators but could deter seed dispersers,
harming the plant fitness.
Here we report the characterization of the glucosinolates-myrosenase
system from the desert plant Ochradenus baccatus, including the isolation and structure
determination of a novel glucosinolate, O-(α-Arabinosyloxy) Benzyl. We also
describe the use of this glucosinolates-myrosenase system by the plant to reinforce
seed dispersal behavior in predominantly seed predator rodent species.
