Isolation and analysis of differentially expressed genes from peanut in response to challenge with Ralstonia solanacearum

Background: Bacterial wilt caused by Ralstonia solanacearum is the most devastating disease in peanut. Planting resistant peanut cultivars is deemed as the sole economically viable means for effective control of the disease. To understand the molecular mechanism underlying resistance and facilitate breeding process, differences in gene expression between seeds of Rihua 1 (a Virginia type peanut variety resistant to bacterial wilt) inoculated with the bacterial pathogen suspension (10(9) cfu ml(-1)) and seeds of the same cultivar treated with water (control), were studied using the Genefishing (TM) technology. Results: A total of 25 differentially expressed genes were isolated. Expression of genes encoding cyclophilin and ADP- ribosylation factor, respectively, were further studied by real time RTPCR, and full length cDNAs of both genes were obtained by rapid amplification of cDNA ends. Conclusions: The study provided candidate genes potentially useful for breeding peanut cultivars with both high yield and bacterial wilt resistance, although confirmation of their functions through transgenic studies is still needed.