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

Processes that contribute to the overall phenomenon of fruit ripening are not well understood for many soft fruit species, including raspberry (Rubus idaeus L.) Recent biochemical data implicate ethylene and a range of cell wall hydrolases in ripening processes. However, the genes encoding these activities, and others related to ripening, remain to be characterised. With the advent of high-throughput RNA-fingerprinting techniques it is possible to characterise rapidly the changes in gene expression during developmental processes. This paper describes the application of two RNA-fingerprinting techniques (cDNA amplified fragment length polymorphism and differential display reverse transcription-polymerase chain reaction) to the ripening fruit of Rubus idaeus. Copy-DNA tags were isolated representing 34 genes, up-regulated during fruit ripening. The expression profiles of these genes were determined by RNA-blot analysis and their sequences were compared with those in public databases. Potential roles for some of these gene products are considered, providing valuable insights into the processes that underpin fruit ripening. Many of the cDNAs isolated in this study provide tools for the biotechnological improvement of fruit quality.