Peripheral Coding of Sex Pheromones in the Tomato Leaf Miner, Phthorimaea absoluta (Meyrick)

Phthorimaea absoluta releases (E3,Z8,Z11)-tetradeca-3,8,11-trienyl acetate (E3,Z8,Z11-14:OAc) and (E3,Z8)-tetradeca-3,8-dienyl acetate (E3,Z8-14:OAc) with a ratio of 90:10 as the sex pheromone. However, how this pest uses pheromone receptors (PRs) to detect the two pheromone components is unknown. Here, we functionally characterize the PR repertoire of P. absoluta. First, we identified five putative PRs by transcriptome sequencing, i.e., PabsOR4, PabsOR8, PabsOR12a, PabsOR14, and PabsOR17. These receptors are predominantly expressed in the male antennae. Next, we expressed them in Drosophila OR67 neurons and investigated their responses. PabsOR14 and PabsOR8 selectively respond to the main component, E3,Z8,Z11-14:OAc with different sensitivities, while PabsOR17 is tuned to the minor component, E3,Z8-14:OAc. In addition, PabsOR4 weakly responds to both sex pheromone components. Moreover, PabsOR17 and PabsOR4 potently respond to a non-sex pheromone compound, (Z)-7-dodecenyl acetate (Z7-12:OAc). Lastly, we demonstrated that Z7-12:OAc can replace E3,Z8-14:OAc to attract virgin males. Our findings elucidate the peripheral coding of the sex pheromone in P. absoluta, providing a new perspective for controlling it.