Proteomic and metabolomic profiles of larval hemolymph associated with diapause in the cotton bollworm, Helicoverpa armigera

Abstract

BackgroundDiapause is programmed developmental arrest coupled with the depression of metabolic activity and the enhancement of stress resistance. Pupal diapause is induced by environmental signals and is prepared during the prediapause phase. In the cotton bollworm, Helicoverpa armigera, the prediapause phase, which contains two sub-phases, diapause induction and preparation, occurs in the larval stage. Here, we performed parallel proteomic and metabolomic analyses on H. armigera larval hemolymph during the prediapause phase.ResultsBy two-dimensional electrophoresis, 37 proteins were shown to be differentially expressed in diapause-destined larvae. Of these proteins, 28 were successfully identified by MALDI-TOF/TOF mass spectrometry. Moreover, a total of 22 altered metabolites were found in diapause-destined larval hemolymph by GC-MS analysis, and the levels of 17 metabolites were elevated and 5 were decreased.ConclusionsThe proteins and metabolites with significantly altered levels play different roles in diapause-destined larvae, including diapause induction, metabolic storage, immune response, stress tolerance, and others. Because hemolymph circulates through the whole body of an insect, these differences found in diapause-destined larvae most likely correspond to upstream endocrine signals and would further influence other organ/tissue activities to determine the insect’s fact: diapause or development.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-14-751) contains supplementary material, which is available to authorized users.

Insight into the possible mechanism of the summer diapause ofDelia antiqua(Diptera: Anthomyiidae) through digital gene expression analysis

“…Notably, the levels of ferritin were increased in the entire summer diapausing process. Ferritin has been associated with a stress response in early diapause of N. vitripennis (Wolschin & Gadau, ) and Helicoverpa armigera (Zhang et al ., ). As an important ion protein, the accumulation of ferritin in SD can prevent destructive oxidative stress triggered by free iron.…”

Dormancy in Embryos: Insight from Hydrated Encysted Embryos of an Aquatic Invertebrate

“…These include glutathione S-transferase (GST) with antioxidant activity, protecting cellular components from oxidative damage. Ferritin is one of the most abundant proteins in dormant RE and E0 and shows higher abundance in diapausing insects (123,124) and copepods (125). It has been shown that the concentration of ferritin increases in response to stresses such as anoxia (126).…”

Insect Heat Shock Proteins During Stress and Diapause

“…Hsp90, known to bind steroid receptors and kinases, diminishes and may reflect low ecdysteroid levels (99). Metabolomic and proteomic analyses show that the larval brain and hemolymph of the cotton bollworm, Helicoverpa armigera, upon induction of and preparation for diapause, display several regulatory proteins and biochemical changes, but no HSPs are observed at this early prediapause stage (100,101), as is true for the Asian tiger mosquito, Aedes albopictus, as it prepares for adult reproductive diapause (68). Hsp20.7 and Hsp90 decline in the brain during diapause of H. armigera, while Hsp21.4 rises (13, 60), as does Hsp70 mRNA (4).…”