Abstract:

To select proper internal control genes for gene expression analysis in mycete plant pathogen Phytophthora cactorum, the expression patterns of 4 housekeeping genes encoding ubiquitin-conjugating enzyme (Ubc), β-tubulin (Tub-b), 40S ribosomal protein S3A (WS21) and a protein of the BAR-domain family (WS41) were investigated by real-time RT-PCR during the developmental and strawberry infection stages of P. cactorum in this study. Their expression stability was also compared to each other using the softwares geNorm, NormFinder and BestKeeper. The results showed that the designed primers of 4 housekeeping genes based on the sequences deposited in the public databases and the homologous sequences in other Phytophthora species worked well with high amplification efficiency, effectivity and specificity to P. cactorum. It was found that Ubc was the most stable gene across the investigated developmental (mycelium, sporangium, zoospore and cyst germination) and strawberry infection stages (3, 5 and 7 d post-inoculation), and the combination of Ubc and WS41 could be served as internal control combination genes for normalization of real-time RT-PCR data. The results of this study provided important internal control genes for gene expression analysis of P. cactorum by real-time RT-PCR and valuable clues to the similar studies in other Phytophthora species.