RECOMBIO: Recombination mechanisms in higher plants and their use in plant biotechnology

• Unité de recherche: PCRD EU
• Numéro de projet: 96.0402-2
• Titre du projet anglais: RECOMBIO: Recombination mechanisms in higher plants and their use in plant biotechnology

Mots-clé (Anglais)

Plant genetics; somatic recombination; recombination mutants; environmental stress; plant adaptation; gene targeting

Autre Numéro de projet (Anglais)

EU project number: BIO4CT972028

Programme de recherche (Anglais)

EU-programme: 4. Frame Research Programme - 4.1 Biotechnology

Description succincte (Anglais)

See abstract

Partenaires et organisations internationales (Anglais)

Coordinator: Amica-Science-EEIG (UK)

Résumé des résultats (Abstract) (Anglais)

For all organisms, homologous recombination is important to ensure genetic flexibility, and is also a major pathway for the repair of DNA lesions. Whereas many of the genetic pathways and proteins involved in DNA repair and recombination are known in prokaryotes (bacteria), simple eukaryotes (yeast) and higher animal cells, comparably little is known about these components in plants. The ongoing sequence analysis of plant genomes revealed the presence of many genes similar to already characterized recombination and repair genes from other organisms. This homology-based gene identification has several drawbacks: even if a plant gene is similar to a well-studied counterpart from a different organism, the exact biological function or the regulation of the encoded protein may differ. In addition, plant-specific factors involved in DNA repair and recombination can not be identified by this approach.
We have chosen a functional approach to identify plant factors directly or indirectly involved in the process of homologous recombination: a screen for plant mutants with a strongly increased spontaneous somatic recombination frequency.
An Arabidopsis thaliana line carrying a luciferase-based recombination-reporter transgene that can be assayed in vivo was used as target for Agrobacterium-mediated T-DNA activation-tagging mutagenesis. 20.000 independent Arabidopsis transformants were screened for their somatic recombination frequency using a high-sensitivity CCD camera. Plants with an increased number of recombination events were observed with a frequency of about 2‰. Methods were established to allow a rapid molecular analysis of the 'recombination-up' plants and begin the cloning and characterization of the affected plant genes. Currently, the link between potential target genes and the observed hyper-recombination phenotype is analyzed by co-segregation analysis of phenotype and specific T-DNAs, and over- or underexpression studies with candidate genes.
Taken together, this activation-tagged Arabidopsis mutant collection will be an important tool for the isolation of genes involved in the enzymology or regulation of homologous recombination and DNA repair in higher plants.

Références bases de données (Anglais)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 96.0402-2