Profiling of changes in gene expression during raspberry (Rubus idaeus) fruit ripening by application of RNA fingerprinting techniques

Processes that contribute to the overall phenomenon of fruit ripening are n ot well understood for many soft fruit species, including raspberry (Rubus idaeus L.) Recent biochemical data implicate ethylene and a range of cell w all hydrolases in ripening processes. However, the genes encoding these act ivities, and others related to ripening, remain to be characterised. With t he advent of high-throughput RNA-fingerprinting techniques it is possible t o characterise rapidly the changes in gene expression during developmental processes. This paper describes the application of two RNA-fingerprinting t echniques (cDNA amplified fragment length polymorphism and differential dis play reverse transcription-polymerase chain reaction) to the ripening fruit of Rubus idaeus. Copy-DNA tags were isolated representing 34 genes, up-reg ulated during fruit ripening. The expression profiles of these genes were d etermined by RNA-blot analysis and their sequences were compared with those in public databases. Potential roles for some of these gene products are c onsidered, providing valuable insights into the processes that underpin fru it ripening. Many of the cDNAs isolated in this study provide tools for the biotechnological improvement of fruit quality.