Some Japonica rice plant varieties show the resistance to the whitebacked planthopper (S. furcifera) and the varieties produce ovicidal compound, benzyl benzoate, to kill their eggs lying in the rice plant. We have tried to elucidate the mechanism for inducing the production of the benzyl benzoate by the Japonica rice varieties. The active 80% MeOH/H2O extract was chromatographed on ODS open column and separated into 6 fractions; 100% H2O, 20% MeOH/H2O, 60% MeOH/H2O, 80% MeOH/H2O, 100% MeOH, 100% EtOH. Of these 6fractions, 100% MeOH and 100% EtOH fractions evidently induced benzyl benzoate at 43.95μg/g of fresh rice plant(frp) and 31.04μg/gfrp, respectively. The active compounds were submitted to analyses by using NMR and GC- and LC-MS inorder to elucidate the structure. We find elicitors to induce with S. furcifera. The elicitors are in the female of S. furcifera and the structures of elicitors are species of phospholipid and glycerol.

We elucidate the mechanism for inducing the production of ovicidal benzyl benzoate by Japonica rice varieties to kill eggs of the whitebacked planthopper, Sogatellafurcifera(Horváth), lying in the rice plant. Even when subjected to physical damage by a needle or damage with water, the rice plant produced no benzyl benzoate. However, significant benzyl benzoate was produced when the plant was damaged with a methanol extract or homogenate of S.furcifera. The extract of the male did not induce the production of benzyl benzoate, but that of the female did. We concluded from these results that benzyl benzoate was induced by some elicitor(s) in the female of S.furcifera.