The main objectives are as follows:
* The mapping of genes responsible for aluminium tolerance in maize by using genetic and molecular methods.
* The identification of genes associated with aluminium tolerance in maize and analysis of their expression.
* The identification of Arabidopsis ecotypes tolerant and sensitive to aluminium and analysis of the modification of the rhizosphere.
* Production of transgenic plants altered in the expression of genes involved in the biosynthesis of organic acids.
* Analysis of specific root epidermis promoters in transgenic tobacco and maize plants.
The project intends to provide tools for the analysis of aluminium tolerance in maize such as molecular markers and cDNA clones corresponding to genes induced or repressed in different aluminium conditions. A screening in a model plant, Arabidopsis thaliana, will be carried out in order to obtain tolerant and sensitive ecotypes. Transgenic tobacco and maize plants with altered organic acid biosynthesis will be obtained and they will be analyzed for aluminium tolerance. Transgenic plants will also be used to analyze promoters specific for root epidermis.
The key activities envisaged are:
* Mapping of maize genes involved in aluminium tolerance using available segregant populations and molecular marker methodology.
* Identification of genes involved in aluminium tolerance by differential display and differential screening between tolerant and sensitive maize lines in the presence or absence of aluminium. Analysis of the structure and expression of selected clones.
* Production of transgenic and tobacco plants overexpressing bacterial citrate synthase and overexpression of PEPC and MDH. Analysis of variations in organic acid production and secretion in root exudates. Study of the tolerance of the transgenic plants to aluminium.
* Screening of Arabidopsis thaliana ecotypes for aluminium sensitivity. Analysis of root exudates and initial genetic analysis.
* Analysis of promoters encoding root-specific malic enzyme in tobacco and maize and analysis of the specificity of expression in the epidermis.
Funding SchemeCSC - Cost-sharing contracts