Olive fruits infested with olive fly larvae respond with an ethylene burst and the emission of specific volatiles.
Olive fly (Bactrocera oleae R.) is the most harmful insect pest of olive (Olea europaea L.) which strongly affects fruits and oil production. Despite the expanding economic importance of olive cultivation, up to now, only limited information on plant responses to B. oleae is available. Here, we demonstrate that olive fruits respond to B. oleae attack by producing changes in an array of different defensive compounds including phytohormones, volatile organic compounds (VOCs), and defense proteins. Bactrocera oleae-infested fruits induced a strong ethylene burst and transcript levels of several putative ethylene-responsive transcription factors became significantly upregulated. Moreover, infested fruits induced significant changes in the levels of 12-oxo-phytodienoic acid and C12 derivatives of the hydroperoxide lyase. The emission of VOCs was also changed quantitatively and qualitatively in insect-damaged fruits, indicating that B. oleae larval feeding can specifically affect the volatile blend of fruits. Finally, we show that larval infestation maintained high levels of trypsin protease inhibitors in ripe fruits, probably by affecting post-transcriptional mechanisms. Our results provide novel and important information to understand the response of the olive fruit to B. oleae attack; information that can shed light onto potential new strategies to combat this pest.
CNR-Institute of Biosciences and Bioresources (IBBR), Perugia, 06128, Italy.
Fiammetta
F
Alagna
Department of Molecular Ecology, Max Planck Institute of Chemical Ecology, Jena, 07745, Germany.
Mario
M
Kallenbach
CNR-Institute of Biosciences and Bioresources (IBBR), Perugia, 06128, Italy.
Andrea
A
Pompa
CNR-Institute of Biosciences and Bioresources (IBBR), Perugia, 06128, Italy.
Francesca
F
De Marchis
Department of Agronomy, University of Naples "Federico II", 80055, Portici, Italy.
Rosa
R
Rao
Department of Molecular Ecology, Max Planck Institute of Chemical Ecology, Jena, 07745, Germany.
Ian T
IT
Baldwin
Department of Molecular Ecology, Max Planck Institute of Chemical Ecology, Jena, 07745, Germany.
Gustavo
G
Bonaventure
CNR-Institute of Biosciences and Bioresources (IBBR), Perugia, 06128, Italy.
Luciana
L
Baldoni
D000818:Animals; D005030:Ethylenes / Q000378:metabolism*; D005247:Feeding Behavior; D035264:Flowers / Q000235:genetics; D005638:Fruit / Q000235:genetics / Q000469:parasitology*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007814:Larva; D008954:Models, Biological; D031658:Olea / Q000235:genetics / Q000469:parasitology*; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology*; D010937:Plant Growth Regulators / Q000378:metabolism; D011480:Protease Inhibitors / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D033621:Tephritidae / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000378:metabolism*
D005030:Ethylenes; D010937:Plant Growth Regulators; D011480:Protease Inhibitors; D012333:RNA, Messenger; D055549:Volatile Organic Compounds; C036216:ethylene
Bactrocera oleae; Olea europaea; biotic stress; phytohormones; plant defense; volatile organic compounds