 The glucosinolate-myrosinase defensive system is packaged in the plant in a unique manner.Plants store myrosinase glucosinolates by compartmentalization, such that the latter is released and activated only when the plant is under attack.Myrosinase is stored largely as myrosin grains in the vacuoles of particular idioblasts called myrosin cells, but have also been reported in protein bodies or vacuoles, and as cytosolic enzymes that tend to bind to membranes.