Plant secondary metabolites (PSMs) of Brassicaceae and their role in plant defense against insect herbivores – A review

Abstract

The genus Brassica includes economically important oilseed and vegetable plants. A number of insect pests are known to infest these crops and cause significant losses in yield. The plants in the family Brassicaceae have multiple defense mechanisms to overcome or reduce the damage by these pests including defensive biochemicals. These Plant Secondary Metabolites (PSMs) involve myrosinase-glucosinolate system, different volatile com-pounds, lectins, phytoalexins and phytoanticipins. While some of the compounds are always present in the plant system, the others are synthesized after herbivore attack. These compounds can either directly protect the plant by having effect(s) on insects’ biology/behaviour or indirectly by attracting the natural enemies of the pests. Because of these secondary compounds, Brassicas have the potential to be used in pest management such as biofumigation against soil pests, as trap crops and cover crops and hence, can be a part of push-pull strategy. An attempt has been made to review these compounds in Brassicas, their role in defense against insects and potential in pest management.