2012 Program (PDF) - International Society of Chemical Ecology

Monday 23rd July, 11:00 – 11:15 hA sugar gustatory receptor identified from the foregut of cotton bollwormHelicoverpa armigeraWEI XU, HUIJIE ZHANG, ALISHA ANDERSONCSIRO Ecosystem Sciences, Black Mountain, ACT, AUSTRALIAHelicoverpa armigera (Hubner) is one of the most polyphagous and cosmopolitan pestspecies, the larvae of which feed on numerous important crops such as cotton, peanuts,soybeans or maize. The gustatory system is critical in guiding insect feeding behaviours.Here we identify one gustatory receptor, HarmGR12, from H. armigera, which shows highidentity to DmGR43a from Drosophila melanogaster and BmorGR9 from Bombyx mori.Reverse transcriptase PCR (RT-PCR) revealed HarmGR12 is highly expressed in larvalforegut, with little or no expression in other chemosensory tissues. Membrane topologystudies indicated that, like two previously studied B. mori GRs, HarmGR12 has an invertedtopology relative to G protein-coupled receptors, an intracellular N-terminus and anextracellular C-terminus. Calcium imaging studies confirmed HarmGR12 is a sugar receptorshowing a high response to D-Fructose, D-Galactose and D-Maltose but not to the othersugars tested. This highly-expressed foregut-specific gustatory receptor may contribute tothe control of larval feeding behaviour.Keywords: Helicoverpa armigera, gustatory receptor, foregut, sugar receptor49