Tweedle gene family of Drosophila suzukii (Matsumura) larva enhances the basal tolerance to cold and hypoxia

BACKGROUND: Drosophila suzukii (Matsumura) is considered a quarantine pest in the A2 list because it causes serious infection and huge economic losses. Cold and controlled atmosphere treatments have been used to control immature stage pests in fresh fruits. Herein, the basal tolerance response of D. suzukii egg, larva and pupa to cold and hypoxia stress were studied, and underlying transcriptome mechanisms in the larva were pinpointed. RESULTS: The third instar was more tolerant than 12-h-old egg and 8-day-old pupa when treated at 3 degrees C + 1% O-2 for 7 days, with 34.00% +/- 5.22% larval survival. Hypoxia influenced the effect of cold treatment on D. suzukii. Larval survival decreased at 3 degrees C + 1% O-2, but increased at 0 degrees C + 1% O-2. Survival increased with temperature between 0 and 5 degrees C + 1% O-2, but decreased significantly at 25 degrees C + 1% O-2. RNA-sequencing results showed that the Tweedle (Twdl) family was upregulated and uniquely enriched in larvae treated at 3 degrees C + 1% O-2. In addition, RNA interference-mediated silencing of a key Twdl gene reduced the survival rate after cold and hypoxia treatment. CONCLUSION: Hypoxia was able to influence the effect of cold treatment on the survival of D. suzukii positively or negatively. Structural constituents of the chitin-based cuticle, in particular Twdl genes, body morphogenesis, and ATP synthesis-coupled proton transport were involved in the tolerance to cold and hypoxia. In future, the Twdl gene could be used as a nanocarrier delivering RNA pesticides to control D. suzukii in the field and so prevent its worldwide spread. (c) 2023 Society of Chemical Industry.