LAUSR

Abstract Worldwide, the increasing number of insecticide-resistant insects is one of the main problems in agriculture not only in the field but also in storage. The lesser grain borer, Rhyzopertha dominica, is one of the cosmopolitan insects that infests a wide range of stored cereals and related commodities. However, strongly resistant populations of R. dominica have been detected in Australia that could threaten the market access of infested commodities. A resistant strain originally collected in Australia showed extremely high levels of resistance to phosphine, around 100-fold higher than that of the susceptible strain. The resistant strain has a mutation in dihydrolipoamide dehydrogenase (DLD), which is a well-known phosphine resistance mechanism in some coleopteran insects. Thus, here, we tried to identify their phosphine resistance mechanism based on transcriptome analysis using RNA-Seq in the adult stage in addition to the mutation effect in R. dominica. Over 1 Gb was sequenced in each replication (susceptible and resistant), and similar to the synergistic test, cytochrome P450, carboxylesterase, CbE and glutathione S-transferase, GST gene families were significantly differently expressed in two strains (p