Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field
Christelle Aurélie Maud Robert, Matthias Erb, Ivan Hiltpold, Bruce Elliott Hibbard, Mickaël David Philippe Gaillard, Julia Bilat, Jörg Degenhardt, Xavier Cambet-Petit-Jean, Ted Turlings & Claudia Zwahlen
| Résumé |
Genetic manipulation of plant volatile emissions is a promising tool
to enhance plant defences against herbivores. However, the potential
costs associated with the manipulation of specific volatile synthase
genes are unknown. Therefore, we investigated the physiological and
ecological effects of transforming a maize line with a terpene
synthase gene in field and laboratory assays, both above- and below
ground. The transformation, which resulted in the constitutive
emission of (E)--caryophyllene and -humulene, was found to
compromise seed germination, plant growth and yield. These
physiological costs provide a possible explanation for the
inducibility of an (E)--caryophyllene-synthase gene in wild and
cultivated maize. The overexpression of the terpene synthase gene
did not impair plant resistance nor volatile emission. However,
constitutive terpenoid emission increased plant apparency to
herbivores, including adults and larvae of the above ground pest
Spodoptera frugiperda, resulting in an increase in leaf damage.
Although terpenoid overproducing lines were also attractive to the
specialist root herbivore Diabrotica virgifera virgifera below
ground, they did not suffer more root damage in the field, possibly
because of the enhanced attraction of entomopathogenic nematodes.
Furthermore, fewer adults of the root herbivore Diabrotica
undecimpunctata howardii were found to emerge near plants that
emitted (E)--caryophyllene and -humulene. Yet, overall, under the
given field conditions, the costs of constitutive volatile
production overshadowed its benefits. This study highlights the
need for a thorough assessment of the physiological and ecological
consequences of genetically engineering plant signals in the field
to determine the potential of this approach for sustainable pest
management strategies. |
| Mots-clés |
terpenoid-engineered plants, volatile emission costs, volatile emission benefits, (e)-beta-caryophyllene, belowground herbivory, aboveground herbivory, induced resistance, trade-offs, spodoptera-littoralis, terpenoid metabolism, nicotiana-attenuata, larval development, insect herbivores, indirect defenses, ecological costs, background odor |
| Citation | Robert, C. A. M., Erb, M., Hiltpold, I., Hibbard, B. E., Gaillard, M. D. P., Bilat, J., Degenhardt, J., Cambet-Petit-Jean, X., Turlings, T., & Zwahlen, C. (2013). Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field. Plant Biotechnology Journal, 11(5), 628-639. |
| Type | Article de périodique (Anglais) |
| Date de publication | 2013 |
| Nom du périodique | Plant Biotechnology Journal |
| Volume | 11 |
| Numéro | 5 |
| Pages | 628-639 |