Differential gene expression analysis in juice vesicles of different citrus species

Citrus is an important commercial fruit crop in the world. Several reproductive barriers limit the application of conventional breeding for cultivar improvement. Genetic engineering and other developments in molecular biology offer the possibility of expanding the number of gene combinations, including transgenic plants which could improve disease resistance and other valuable traits. The differential gene expression patterns can be used to isolate new genes by differential display technique. We used the differential display technique adapted to agarose gels using 96 primer combinations to compare differential gene expression in juice sacs of mature fruits of Dancy tangerine, Rio Red grapefruit and Golden grapefruit. A total of 78 differential cDNAs were identified, of which 71 were successfully re-amplified. Reverse northern analysis confirmed that 17 cDNAs were truly differentially expressed mRNAs. From the 17 cDNAs, thirteen were cloned, sequenced and compared to the non-redundant GenBank database. The two that were similar to genes of horticultural importance were chosen for further studies. (Abstract shortened by UMI.)...