The management of diamondback moth and other crucifer pests

Coping with glucosinolates: disarming the mustard oil bomb*

Heiko Vogel, Jürgen Kroymann, Andreas Ratzka and Thomas Mitchell-Olds

Max-Planck-Institute for Chemical Ecology, Department of Genetics & Evolution, Carl-Zeiss-Promenade 10, 07745 Jena, Germany. Corresponding author: [email protected]

Abstract Glucosinolates are plant secondary metabolites found in crucifers. Upon tissue rupture, e.g. caused by a chewing insect, glucosinolates are hydrolysed by an endogenous plant enzyme, myrosinase. This leads to the formation of a variety of breakdown products (isothiocyanates, nitrile and others) that are toxic to many insect species, especially generalist herbivores. However, insects specialized on crucifers survive despite this glucosinolate-myrosinase defence system. In many cases, glucosinolates and their breakdown products are even utilized to locate suitable host plants. Little is known about the metabolic processes that allow specialist and some generalist insects to survive on glucosinolate containing plants. To elucidate which properties enable herbivorous insects (especially diamondback moth) to overcome their hosts' defences, we use a variety of molecular biological and genetic approaches; e.g. EST sequencing and transcript profiling. These allowed the identification of a so-called “glucosinolate sulfatase” gene, whose gene product prevents the formation of toxic glucosinolate breakdown products.

*More detailed information may be found in: Ratzka A, Vogel H, Kliebenstein DJ, Mitchell-Olds T & Kroymann J. 2002. Disarming the mustard oil bomb. Proceedings of the National Academy of Sciences of the USA 99: 11223–11228.

Proceedings of the 4th International Workshop, Nov. 2001, Melbourne, Australia 159