Project description:This experiment constitutes an expression profiling approach to identify genes differentially regulated during the symbiotic interaction between the model legume Medicago truncatula and the nitrogen-fixing bacterium Sinorhizobium meliloti. Macro- and microarrays containing 6144 probes were generated on the basis of three cDNA libraries dedicated to the study of root symbiotic interactions. The experiment performed on wild-type and symbiotic mutant material led to the identification of genes either up- or down-regulated at different stages of the nodulation process.