Dr Herman Wijnen – University of Southampton
Dr Fryni Drizou – Royal Horticultural Society (RHS)
Dr Haruko Okamoto – University of Sussex
The diamondback moth (DBM), Plutella xylostella, is an agricultural pest with worldwide impact on brassica crops (>$5 billion in annual damages).
Its unique glucosinolate sulfatase (GSS) enzymes allow it to specialize on cruciferous host plants by evading their glucosinolate/myrosinase defence system1. In preliminary studies, we established that herbivory by DBM caterpillars is controlled both by environmental light and their internal daily timekeeping systems. Moreover, the expression of DBM GSS genes exhibits circadian rhythmicity. This project aims to elucidate abiotic and biological determinants of DBM herbivory of its host plants. It will complement ongoing research focused on circadian control of herbivory in the DBM caterpillar by concentrating on environmentally-controlled defence mechanisms in cruciferous plants (Brassica rapa and Arabidopsis thaliana). The following Specific Objectives will be pursued: SO1) Identify how host plant glucosinolate production and herbivory by DBM are affected by (a) glucosinolate biosynthesis and daily timekeeping in the host plant, (b) daily environmental cycles in light and temperature. The latter will simulate representative light/temperature cycles for the UK and explicitly explore the predicted impact of light pollution and global warming. SO2) Identify changes in plant and DBM expression profiles that are closely associated with changes in herbivory across different environmental contexts.