Insect juvenile hormones in plants

Abstract

Abstract In the defence against insect herbivory, plants may produce compounds which interfere with the insect endocrine system [ 2, 3, 4 ]. The focus of this review is to provide an overview of plant secondary metabolites which act either as insect juvenile hormone (JH) mimics or interfere with JH biosynthesis. Juvenile hormones are sesquiterpenoids which are involved in the regulation of developmental processes such as metamorphosis and reproduction in most insect species [ 5 ]. The first section of this review provides an overview of insect JHs, including their physiological action and biosynthesis in hemimetabolous insects such as the cockroach, Diploptera punctata , and their general chemistry. In the next part, examples of phytochemicals which act as JH mimics (juvenoids) or which inhibit JH biosynthesis will be presented, illustrating the diversity of compounds which are able to interfere with the endocrine system of the insect. Finally, a unique example of the production of insect juvenile hormone III (JH III), methyl-10 R ,11-epoxy-3,7,11-trimethyl 2 E ,6 E -dodecadienoate, in the sedge Cyperus iria L. will be presented and the possible biological role(s) of this compound discussed.