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Practical strategies for environmental risk assessment & minimising the potential impact of GMOs on non-target species (CB02021 from 2003/04) - RG0126

In this proposal we intend to build on our knowledge of the microbial ecology and genetics of plant associated bacteria. We will utilise a model system that combines our well described PCA producing bacterium1,13 and chitinase producing plants (initially tobacco5 will be studied, and wheat and rape as they become available). These GM-bacteria and GM-plants carry novel antifungal compounds (AFCs) for the suppression of fungal phytopathogens and provide ideal systems with which to assess impact on microbial ecosystem function in agricultural soils (see Figs 1 and 2).

We have developed generic methods that facilitate phylogenetic, molecular and biological analyses of the activity of microbial communities. These methods will be applied to determine impact by monitoring changes in succession, activity, biomass and diversity in the mycorrhizal and rhizobacterial community in response to GM-BCA inocula and chitinase producing plants. The techniques include culture independent community profiling by 18S and 16S rRNA DGGE/TGGE, the measure of ecosystem function by enzymatic assays to compare the diversity of the active rhizobacteria purified by CTC/ flow-cytometry, and histological analysis of the mycorrhizal biomass and colonization. In all the proposed objectives these established methods will be applied to samples collected under a standard sampling regimen (see workpackages and milestones for details). By standardising sampling and analytical methods it will be possible to compare data and optimise output.

1. To evaluate the ecological impact and fate of a rhizocompetent bacteria, Pseudomonas fluorescens SBW25, modified to express phenazine 1-carboxylic acid (PCA) for the enhanced protection of agricultural crops from fungal disease.

2. Determine how the impact of PCA producing bacteria compares to the impact of chitinase producing plants, tobacco then wheat and rape.

3. Determine whether a biocontainment strategy for the niche directed expression of PCA reduces perturbation to ecosystem function. A promoter Ppui3 has been identified in SBW25 that is induced only in the presence of the germinating oospores of Pythium ultimum, the causative agent of damping-off disease.

4. Undertake small scale field releases of the bacterial genetically modified biological control agents (GM-BCA) to test and provide science based advice to the regulatory authorities on the likely environmental impact and suitability of methods for making assessment.

Project Documents
• Final Report : Strategies for risk assessment minimising the environmental impact of fungal disease suppressing GM bacteria and plants on non-target species   (310k)
• Final Report - Annex : Strategies for risk assessment minimising the environmental impact of fungal disease suppressing GM bacteria and plants on non-target species   (1137k)
Time-Scale and Cost
From: 2002

To: 2005

Cost: £85,151
Contractor / Funded Organisations
Natural Environment Research Council
Disease Control              
GM Risk Assessment              
Fields of Study
Biotechnology and GMOs