The octopamine receptor, OA2B2, modulates stress resistance and reproduction in Nilaparvata lugens Stål (Hemiptera: Delphacidae)

• Published in: Insect molecular biology 2022-02, Vol.31 (1), p.33-48
• Main Authors: Zhang, Y. J., Jiang, L., Ahamd, S., Chen, Y., Zhang, J. Y., Stanley, D., Miao, H., Ge, L. Q.
• Format: Article
• Language: English
• Subjects: abiotic stressors; Animals; Body weight; Cereal crops; Eggs; Fat body; fecundity; Female; Hatching; Heat resistance; Hemiptera - metabolism; High temperature; Hypotheses; Male; Nilaparvata lugens; Octopamine; Offspring; Ovaries; Oviposition; Oxidative stress; Population growth; Prostatic Hyperplasia; Protein biosynthesis; Protein synthesis; Proteins; Receptors; Receptors, Biogenic Amine - metabolism; Reproduction; RNA-mediated interference; Starvation; stress resistance; Vitellogenin; Vitellogenins - metabolism; β‐adrenergic‐like octopamine type 2 (OA2B2)
• ISSN: 0962-1075; 1365-2583
• DOI: 10.1111/imb.12736

The brown planthopper (BPH), Nilaparvata lugens (Stål) is a resurgent pest of rice crops throughout Asia. We recently discovered that octopamine (OA) and OA2B2 operate in the BPH mating system, where it mediates a wide range of molecular, physiological and behavioural changes. Here, we report on outcomes of experiments designed to test the hypothesis that OA/OA2B2 signalling mediates responses to three abiotic stressors, starvation, high temperature (37 °C), and induced oxidative stress. We found per os RNAi‐mediated OA2B2 silencing led to significantly decreased survival, measured in days, following exposure to each of these stressors. We selected a biologically costly process, reproductive biology, as a biotic stressor. Silencing of OA2B2 led to decreased total protein content in ovaries and fat bodies, downregulated expression of vitellogenin (Vg) and Vg receptor (VgR), inhibited fat body Vg protein synthesis, shortened the oviposition period, prolonged the preoviposition period, reduced the number of laid eggs, body weight and female longevity. In addition, the silencing treatments also led to inhibited ovarian development, and ovarian Vg uptake, reduced numbers of egg masses and offspring and lower hatching rates and population growth index. These data support our hypothesis that OA2B2 acts in mediating BPH resistance to biotic and abiotic stressors. Starvation, high temperatures and oxidative stress‐induced OA2B2 expression in BPH. Depletion of OA2B2 by RNAi reduced BPH stress resistance under abiotic stresses. RNAi‐mediated OA2B2 led to reduced number of eggs laid, number of offspring.