FORWARDLOOK 06/03/17 Future crops may be genetically engineered to release pheromones normally produced by insects to warn of predators. Scientists working at Rothamstead Research institute in the United Kingdom have genetically engineered wheat crops to release pheromones that insects release when they are attacked by predators.
High crop yields depend on the use of insecticides to control pests Because of the need to use as little of the Earth’s surface for agriculture as possible, it is important that we maintain high crop yields. Today’s crops depend on the use of pest control strategies in order to maintain high yields. Aphids constitute one of the biggest classes of plant-feeding insects. Different strategies to prevent aphids from feeding on crops have largely centred on targeting molecular components of their nervous system.
Most other pest control strategies also target nervous system components, but pesticide resistance is becoming a growing problem. New approaches are needed The pheromones warn other nearby insects that a predator is threatening them, leading the insects to try and escape. Future outlook. Scientific Reports via YOUTUBE 02/03/17 Genetically engineered wheat releases insect pheromones to ward off pests. Ann Bot. 2015 Mar; 115(4): 581–591. Aphid-repellent pheromone E-β-farnesene is generated in transgenic Arabidopsis thaliana over-expressing farnesyl diphosphate synthase2. ANNALS OF BOTANY 20/12/14 Aphid-repellent pheromone E-b-farnesene is generated in transgenic Arabidopsis thaliana over-expressing farnesyl diphosphate synthase2.
SCIENCEMAG 25/06/15 Controversial trial of genetically modified wheat ends in disappointment. A genetically engineered wheat designed to scare away aphids has, in the end, just not proved scary enough.
Researchers had hoped that the wheat modified to emit a warning pheromone would ward off aphids while also attracting their natural enemies, thereby allowing farmers to spray less insecticide. Despite promising signs in the laboratory, the field trial—which made headlines in 2012 after opponents of genetic modification (GM) threatened to obstruct it—failed to show any effect. “It was disappointing news,” says Paul Temple, a wheat farmer with the U.K. Agriculture and Horticulture Development Board, which was not involved in the research. Aphids can cause major headaches for wheat growers. Huw Jones, a molecular biologist, and other scientists at Rothamsted Research, a mainly publicly funded agricultural research station in Harpenden, U.K., wanted to exploit this alarm to help defend wheat plants. NATURE INSTITUTE - JULY 2015 - Pheromone-Producing GM Wheat Does Not Repel Pests in Field Trials.
Posted: July, 2015 Pheromone-Producing GM Wheat Does Not Repel Pests in Field Trials The pheromone (E)-β-farnesene is known to repel pest aphids from plants that they would otherwise feed on.
It also attracts natural enemies of aphids such as parasitic wasps. Wheat plants (Triticum aestivum) were genetically modified to produce and emit this pheromone. The genetic construct contained chemically synthesized gene sequences. The researchers first grew the GM wheat plants in controlled greenhouse conditions. When aphids were raised on the GM wheat plants for five generations in the lab, and then tested, one species of aphids hardly avoided feeding on leaves with pheromones, while another species was not at all repelled by them. SEPPI OVER BLOG 03/07/15 Le blé GM à phéromone est (provisoirement ?) un échec Une communication exemplaire des chercheurs de Rothamsted. Une équipe de Rothamsted Research (Royaume-Uni) a publié un article sur leurs travaux sur un blé génétiquement modifiée pour produire une phéromone censée éloigner les pucerons .
La molécule est le (E)-β-farnesene (Eβf), une phéromone d'alerte. Les chercheurs avaient réussi à faire produire la phéromone de manière stable par le blé, sans autre modification détectable du phénotype. Dans des essais en laboratoire, on avait constaté un effet répulsif sur trois espèces de puceron, ainsi qu'une augmentation de l'activité d'un parasitoïde. Les chercheurs écrivent : « Bien que ces études aient montré un potentiel considérable pour lutter contre les pucerons, les essais en plein champ avec des constructions simple et double n'ont permis de mettre en évidence aucune diminution des pucerons ou augmentation du parasitisme. S'agissant du dernier point, les chercheurs ont en effet émis l'hypothèse que les pucerons pourraient s'habituer à une présence continue de phéromone. NATURE 25/06/15 The first crop plant genetically engineered to release an insect pheromone for defence.
Constructs and plant transformation.
Chemically synthesised gene sequences, codon-optimised for wheat encoding enzymes [(E)-β-farnesene synthase (EβfS) and farnesyl diphosphate synthase (FPPS)], were produced by GenScript Inc. NJ, USA. The enzyme encoded by the EβfS cassette was similar to that found in peppermint (Mentha piperita) and the enzyme encoded by the FPPS cassette had most similarity to the form found in cow (Bos taurus). We chose this heterologous, synthetic gene to express FPP synthase to minimise the chances of co-suppressive silencing and to avoid any post-translational regulation by endogenous enzymes. Four constructs encoding EβfS or FPPS either targeted to the plastid or untargeted were made (ubi1::EβfS, ubi1:: tp:EβfS, ubi1::FPPS, ubi1:: tp:FPPS (Fig.
Air entrainment and GC-MS All plants were grown and maintained in a specialised, air conditioned glass house under controlled conditions (16 h:8 h light:dark regime; 20 °C:15 °C day:night temperatures). Electrophysiology. ROTHAMSTED_AC_UK 25/06/15 Scientists disappointed at results from GM wheat field trial. The results of the GM wheat field trial held by Rothamsted Research in 2012-2013 are published in the scientific journal Scientific Reports today.
The data show that the GM wheat did not repel aphid pests in the field as was hypothesised and was initially seen in laboratory experiments conducted by scientists at the Institute. Aphids are serious pests of wheat and other arable crops cultivated in the UK, transmitting viruses and reducing yield. Farmers spray insecticides to control aphids when infestations become severe due to lack of an alternative approach. ROTHAMSTED RESEARCH 25/06/15 Rothamsted GM Wheat Trial. Is the trial safe?
Thorough risk assessments of this field trial were carried out by the Rothamsted GM Safety Committee and no major safety concern were raised. Following this, the Government's ACRE (the Advisory Committee on Releases to the Environment) said it was "satisfied that all appropriate measures have been taken to avoid adverse effects to human health and the environment from the proposed release" in September 2011, which received coverage through local and national news channels.
ACRE is a statutory advisory committee appointed under section 124 of the Environmental Protection Act 1990 (the EPA) to provide advice to government regarding the release and marketing of genetically modified organisms (www.defra.gov.uk/acre/). As part of the ACRE process, there was a 60 day public consultation period 20th June to 19th Aug 2011, with input from organisations, e.g.
Can the genes move into surrounding areas? Might animals eat the seeds?