Metabolomic analysis of diapausing and noni-diapausing larvae of the European corn borer Ostrinia nubilalis (Hbn.) (Lepidoptera: Crambidae)

Abstract

In this study, an 1H-NMR-based metabolomic approach was used to investigate the biochemical mechanisms of diapause and cold hardiness in diapausing larvae of the European corn borer Ostrinia nubilalis. Metabolomic patterns in polar hemolymph extracts from non-diapausing and diapausing larvae of O. nubilalis were compared. Analysis indicated 13 metabolites: 7 amino acids, glycerol, acetate, citrate, succinate, lactate and putrescine. Results show that diapausing larvae display different metabolomic patterns compared to active non-diapausing larvae, with predominant metabolites identified as glycerol, proline and alanine. In specific diapausing larvae initially kept at 5 °C then gradually chilled to -3 °C and -16 °C, alanine, glycerol and acetate were predominant metabolites. 1H-NMR spectroscopy provides new insight into the metabolomic patterns associated with cold resistance and diapause in O. nubilalis larvae, suggesting distinct metabolomes function in actively developing and diapausing larvae.