The first crop plant genetically engineered to release an insect pheromone for defence

Abstract

Insect pheromones offer potential for managing pests of crop plants. Volatility and instability are problems for deployment in agriculture but could be solved by expressing genes for the biosynthesis of pheromones in the crop plants. This has now been achieved by genetically engineering a hexaploid variety of wheat to release (E)-β-farnesene (Eβf), the alarm pheromone for many pest aphids, using a synthetic gene based on a sequence from peppermint with a plastid targeting amino acid sequence, with or without a gene for biosynthesis of the precursor farnesyl diphosphate. Pure Eβf was produced in stably transformed wheat lines with no other detectable phenotype but requiring targeting of the gene produced to the plastid. In laboratory behavioural assays, three species of cereal aphids were repelled and foraging was increased for a parasitic natural enemy. Although these studies show considerable potential for aphid control, field trials employing the single and double constructs showed no reduction in aphids or increase in parasitism. Insect numbers were low and climatic conditions erratic suggesting the need for further trials or a closer imitation, in the plant, of alarm pheromone release.

Semiochemicals from plants and insects on the foraging behavior of Platygastridae egg parasitoids

“…(Simpson et al, 2011;Blassioli-Moraes et al, 2013;Colazza et al, 2013). Considering these issues, one alternative is to manipulate the plants to produce and release specific volatiles, which can be done by classical breeding or genetic engineering (Schnee et al, 2006;Kunert et al, 2010;Michereff et al, 2011;Bruce et al, 2015). There is no example in the literature on this subject for transgenic transformed arable crops.…”

Volatile Semiochemical Mediated Plant Defense in Cereals: A Novel Strategy for Crop Protection

“…Cadenza was genetically engineered to emit (E)-β-farnesene using a synthetic gene based on a sequence from peppermint with a plastid targeting amino acid sequence, with or without a gene for biosynthesis of the precursor farnesyl diphosphate [40]. In the laboratory bioassay, volatiles from transformed plants were repellent to three species of cereal aphids and significantly enhanced the foraging behaviour of the parasitic wasp Aphidius ervi.…”

“…In the laboratory bioassay, volatiles from transformed plants were repellent to three species of cereal aphids and significantly enhanced the foraging behaviour of the parasitic wasp Aphidius ervi. Although the laboratory studies demonstrated considerable potential for aphid control, field experiment during 2012/2013 cropping seasons did not show evidence of aphid repellence or increased parasitism under field conditions [40]. Modification of the experimental approach has been recommended to further test the promising laboratory results under realistic field conditions [40].…”

“…Although the laboratory studies demonstrated considerable potential for aphid control, field experiment during 2012/2013 cropping seasons did not show evidence of aphid repellence or increased parasitism under field conditions [40]. Modification of the experimental approach has been recommended to further test the promising laboratory results under realistic field conditions [40]. The proposed modifications include considering aphid feeding-associated induced effects and targeting more reliable natural populations of aphids and parasitoids [9,40].…”

“…Modification of the experimental approach has been recommended to further test the promising laboratory results under realistic field conditions [40]. The proposed modifications include considering aphid feeding-associated induced effects and targeting more reliable natural populations of aphids and parasitoids [9,40].…”