Identification of differentially expressed genes during early development of tomato fruit. Characterisation of a novel cDNA coding for a RAD23 protein

Before the onset of ripening, tomato fruit development comprises three distinct phases: fruit set, a cell division phase and a cell expansion phase. In this study, we used the method of mRNA differential display in order to isolate tomato genes specifically expressed during these early phases of fruit development. Among 40 differen-tial bands, nine cDNAs were selected for further investigations based on their identification after nucleotide sequencing. We isolated the full-length cDNA corresponding to one of these fragments, coding for RAD23, a protein involved in the excision repair system, thus providing new sequence information on a poorly characterised protein in plants. All the isolated cDNAs were mapped on the tomato genome and their expression studied by northern blot and semi-quantitative RT–PCR during early fruit development and in vegetative organs of tomato plants. The sequence data are deposited in the GenBank under the accession numbers: AJ270956 (mo5-3C11/1), AJ270957 (mo5-3G12/4), AJ270958 (mo5-3G17), AJ270959 (mo5-3T12), AJ270960 (mo1-6A1), AJ270961 (mo1-6T1), AJ270962 (mo5-10G1), AJ270963 (mo6-20G1), AJ270964 (mo6-MGT2) and AJ243875 (LeRAD23-8 full-length cDNA).