cDNA-AFLP display for the isolation of differentially expressed genes during chicory root development

To identify genes expressed during root enlargment during the early vegetative growth of chicory (Cichorium intybus L.), we used the cDNA-AFLP technology. The radial pattern of chicory roots was investigated by histological analysis to determine the spatial vascular cambium setting. In young plantlets, serial root sections showed that differentiation of secondary tissues occurred along a gradient extending from the apex to the crown. The cDNA-AFLP technique was carried out on total mRNAs extracted from root tissues producing secondary structures and root tissues developing primary structures only. This study reports on the isolation of two transcript-derived fragments (TDFs) referred to as Y-16 and Y-21. Sequence analysis at the protein level showed that Y-16 carries a sequence highly homologous (93% identities) to the amino acid transporter-like protein 1 (AATL 1) from Arabidopsis and Y-21 presents 72% identity to AAD25141.1 Arabidopsis protein. The expression pattern of both these TDFs was analysed by northern blot and showed an over-expression during early development of chicory roots.