In order to analyze the citrus transcriptome 13 standard and 1 normalized full length cDNA libraries were constructed. The RNA for the generation of the full-length cDNA collection was extracted from Citrus clementina fruits, leaves and roots subjected to different abiotic stresses (mostly drought, salinity and nutritional deficiencies) and at several developmental stages. The 13 standard cDNA libraries were made with RNA extracted from specific tissues (fruit, leaf or root) at particular stages (early development, maturation, senescence) or subjected to a single stress condition (drought, salinity, iron chlorosis). The plant material was collected from Citrus clementina, Cleopatra mandarin and Carrizo citrange. From the normalized full length cDNA library, 37.811 ESTs were single-pass sequenced and for the standard libraries 15.000 readings are expected. The Bioinformatics analysis includes the assembly of the 52.000 readings and the annotation of the unigenes obtained. Several biological aspects of citrus are being addressed through the comparison of the citrus unigene set with those from Arabidopsis thaliana and Oryza sativa. Special attention is being taken with sequences that show no similarity with these species. The assembly of the 37.811 ESTs from the normalized full length cDNA library has rendered so far 6499 singletons and 5202 contigs, for a total of about 11700 unigenes. The 15.000 ESTs from the specific cDNA libraries are being currently included in the assembly. An effort is also being made in order to establish the ontologies of the citrus sequences we are analyzing. Details of these studies will be presented in the communication. (Texte intégral)