Vitellogenin from planthopper oral secretion acts as a novel effector to impair plant defenses

Vitellogenin (Vg) is a well-known nutritious protein involved in reproduction nearly all oviparous animals, including insects. Recently, Vg has been detected saliva proteomes of several piercing–sucking herbivorous arthropods, the small brown planthopper (Laodelphax striatellus, SBPH). Its function, however, remains unexplored. We investigated molecular mechanism underlying SBPH orally secreted Vg-mediated manipulation plant–insect interaction by RNA interference, phytohormone and H2O2 profiling, protein–protein studies herbivore bioassays. A C-terminal polypeptide (VgC) SBPH, when into rice plants, acted as novel effector to attenuate host defenses, which turn improved insect feeding performance. Silencing reduced survival on rice. Vg-silenced nymphs consistently elicited higher production, well-established defense rice, whereas expression VgC planta significantly hindered hydrogen peroxide (H2O2) accumulation promoted interacted directly with transcription factor OsWRKY71, induction plant resistance SBPH. These findings indicate function Vg: this effectively weakened H2O2-mediated through its association immunity regulator.