In the case of a non-host barnyard grass, probing of BPH was interrupted before the stylets reached the sieve elements of the phloem because the barnyard grass constitutively contains trans-aconitic acid, which acts as an antifeedant of BPH, in the non-phloem tissues such as parenchyma37,38,39. BPH14 originated from the wild rice O. officinalis mediated sucking inhibition in the phloem25. O. sativa L. and O. officinalis seem to have the same mechanism of resistance, i.e., defense in the phloem, against BPH. The R genes of the NBS-LRR family against BPH might mediate sucking inhibition in the phloem sieve element.