Jinggangmycin-suppressed reproduction in the small brown planthopper (SBPH), Laodelphax striatellus (Fallen), is mediated by glucose dehydrogenase (GDH)

- Fungicide jinggangmycin suppressed reproduction of the small brown planthopper.
- Down-regulated expression of Glucose dehydrogenase (GDH) of JGM-treated females
- Silencing GDH eliminates JGM-induced suppression of reproduction.
- Fatty acid contents in JGM-treated and control + dsGDH females decreased.

The small brown planthopper (SBPH), Laodelphax striatellus (Fallen), is a serious pest insect of rice, wheat, and maize in China. SBPH not only sucks plant sap but also transmits plant disease viruses, causing serious damage. These viruses include rice striped virus disease (RSV disease), black streaked dwarf, and maize rough disease virus. SBPH outbreaks are related to the overuse of pesticides in China. Some pesticides, such as triazophos, stimulate the reproduction of SBPH, but an antibiotic fungicide jinggangmycin (JGM) suppresses its reproduction. However, mechanisms of decreased reproduction of SBPH induced by JGM remain unclear. The present findings show that JGM suppressed reproduction of SBPH (↓ approximately 35.7%) and resulted in the down-regulated expression of glucose dehydrogenase (GDH). GDH-silenced control females (control + dsGDH) show that the number of eggs laid was reduced by 48.6% compared to control females. Biochemical tests show that the total lipid and fatty acid contents in JGM-treated and control + dsGDH females decreased significantly. Thus, we propose that the suppression of reproduction in SBPH induced by JGM is mediated by GDH via metabolic pathways.

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