Expression of a Peppermint (E)-β-Farnesene Synthase Gene in Rice Has Significant Repelling Effect on Bird Cherry-Oat Aphid (Rhopalosiphum padi)

Aphids (Aphididae) cause great damage to economically important cereal crops due to their unparalleled reproductive capacity. The sesquiterpene (E)-beta-farnesene (E beta F) is the alarm pheromone for many aphids, which can be applied to disperse aphids in crops. The peppermint E beta F synthase gene (E beta FS), which enables the production of E beta F in plants to control aphids, has been used in Arabidopsis and tobacco, but has not been studied in rice or other crops yet. Here, we transformed the peppermint E beta FS gene into the rice variety Zhonghua 11 and obtained two homozygous transgenic lines with single-copy insertion. E beta FS expression and E beta F production were then verified by reverse transcription-PCR (RT-PCR)/quantitative real-time PCR (qPCR) and gas chromatography-mass spectrometry (GC-MS). Although only a limited amount of E beta F was detected, the transgenic lines showed a significant repelling effect on bird cherry-oat aphid (Rhopalosiphum padi) compared with the control. Thus, this study provides a valuable reference for improving the resistance against aphids in rice or other important crops.