G01017: Development of methods to study the implications of vector insertion/excision for endogenous DNA function in transgenic peas

Study Duration: October 1999 to November 2002

Contractor: John Innes Centre

This project is studying transgenic peas modified to contain T-DNA insertions and that have the facility to excise an inserted herbicide resistance gene.

The main objectives of this project are as follows:

1. Sequence the T-DNA/plant DNA insertion junctions using a highly specific PCR procedure. These sequences will be placed on the linkage map of the pea genome. Simple PCR techniques for studying the fidelity of excision of a transposable element will be refined.

2. Use the sequence information to screen against the most up-to-date databases using BLAST search tools. Confirm effects of T-DNA insertion on the disruption of the targeted gene.

3. Develop the most efficient and cost-effective methodology to screen intermediary metabolites and protein profiles in simple plant extracts taken from the transgenic peas using a number of powerful techniques.

The technology developed in this project could form the basis for an analytical service, which could be employed routinely to assess any new transgenic crop. The data may be useful for establishing the potential for any unanticipated events occurring when plants are genetically modified.

The method developed, nuclear magnetic resonance (NMR) spectroscopy, was applied to GM and control material and was validated in the early stages of the project by determining that it was possible to detect differences in the levels of metabolites between young and ageing leaves reproducibly. The methodologies were designed to be generic and to be applicable to any transformed crop species.

The project showed that inserting transgenic-DNA into a crop plant with a large genome has a negligible impact on the overall functioning of the plant, as judged by the levels of metabolites detected.

The effects of taking plants through tissue culture can be shown to diminish as successive generations of progeny plants are analysed. In practice, crop plants intended for commercial release have been through many rounds of selection to eliminate these effects.

Techniques developed in this project to survey plant metabolism could be useful in assessing the impact of introducing a transgene on plant performance. Thus, the project has made a valuable contribution to the exploration of techniques that may be of use in refining the safety assessment procedure. These, and other technologies, have been further refined in the G02 programme.

The final report is available from the FSA Library and Information centre.
To obtain a copy, please contact the Enquiry Desk, Dr Elsie Widdowson Library and Information Services, Food Standards Agency, tel: 020 7276 8181/8182 or email: library&info@foodstandards.gsi.gov.uk

Contact: For any enquiries concerning this research project, please contact the relevant Programme contact or email: science@foodstandards.gsi.gov.uk