Molecular interactions between the olive and the fruit fly Bactrocera oleae
1 Dipartimento di Scienze del Suolo, Pianta, Ambiente e Produzioni Animali, Universita’ degli Studi di Napoli Federico II, Via Università 100, Portici, Napoli, 80055, Italy
2 Istituto di Genetica Vegetale, Consiglio Nazionale delle Ricerche, Via della Madonna Alta 130, Perugia, 06128, Italy
3 Dipartimento di Scienze per la Biologia, la Geologia e l’Ambiente, Universita’ del Sannio, Via dei Mulini 59/A, Benevento, 82100, Italy
4 Istituto per il Sistema Produzione Animale in Ambiente Mediterraneo, Consiglio Nazionale delle Ricerche, Via Argine 1085, Napoli, 80147, Italy
5 Dipartimento di Entomologia e Zoologia Agraria “F. Silvestri”, Universita’ degli Studi di Napoli Federico II, Via Università 100, Portici, 80055, Italy
BMC Plant Biology 2012, 12:86 doi:10.1186/1471-2229-12-86Published: 13 June 2012
The fruit fly Bactrocera oleae is the primary biotic stressor of cultivated olives, causing direct and indirect damages that significantly reduce both the yield and the quality of olive oil. To study the olive-B. oleae interaction, we conducted transcriptomic and proteomic investigations of the molecular response of the drupe. The identifications of genes and proteins involved in the fruit response were performed using a Suppression Subtractive Hybridisation technique and a combined bi-dimensional electrophoresis/nanoLC-ESI-LIT-MS/MS approach, respectively.
We identified 196 ESTs and 26 protein spots as differentially expressed in olives with larval feeding tunnels. A bioinformatic analysis of the identified non-redundant EST and protein collection indicated that different molecular processes were affected, such as stress response, phytohormone signalling, transcriptional control and primary metabolism, and that a considerable proportion of the ESTs could not be classified. The altered expression of 20 transcripts was also analysed by real-time PCR, and the most striking differences were further confirmed in the fruit of a different olive variety. We also cloned the full-length coding sequences of two genes, Oe-chitinase I and Oe-PR27, and showed that these are wound-inducible genes and activated by B. oleae punctures.
This study represents the first report that reveals the molecular players and signalling pathways involved in the interaction between the olive fruit and its most damaging biotic stressor. Drupe response is complex, involving genes and proteins involved in photosynthesis as well as in the production of ROS, the activation of different stress response pathways and the production of compounds involved in direct defence against phytophagous larvae. Among the latter, trypsin inhibitors should play a major role in drupe resistance reaction.