PBT selected ten-minute paper 1: Mechanisms of hypoxic adaptation in a storage insect pest, Callosobruchus maculatus

Herbivorous insects not only attack crops in the fields during the growing season, but damage stored grains in the granary after harvest. Each year, storage insect pests cause significant losses in stored products worldwide. Use of modified atmospheres with depleted O₂ and/or elevated CO₂ is an environmentally friendly alternative to currently used fumigants for control of stored grain insect pests. Terrestrial insects need O₂ to generate catabolic ATP, therefore, deprivation of atmospheric O₂ will directly impact insect development and survival. However, many insect species can adapt to O₂ deprivation, and recover from hours to days of hypoxia. This poses a difficulty in using hermetic storage as an environmentally-friendly means to control insect pests. We systematically examined effects of low O₂ on cowpea bruchid development, profiled its transcriptomic responses to hypoxia/hypercapnia, and investigated the involvement of hypoxia-inducible transcription factor 1 (HIF1) in regulating these hypoxia-induced genes through promoter analyses. Results revealed that transcriptomic reconfiguration plays a protective role in the storage pest insects under hypoxia. Better understanding of molecular mechanisms of the remarkable plasticity will potentially help to generate a new approach to post-harvest pest management.