Transcriptome analysis of Luffa cylindrica (L.) Roem response to infection with Cucumber mosaic virus (CMV).

Cucumber mosaic virus (CMV) can cause serious losses in Luffa cylindrica (L.) Roem. Chemical application to control CMV is ineffective and environmentally unfriendly. The development of resistant hybrids is the best way to control CMV disease. Elucidating the virus-host interaction of CMV and molecular basis underlying Luffa spp. resistance against CMV would undoubtedly facilitate breeding for resistance against CMV disease. Transcriptome sequencing was used to analyze differentially expressed genes (DEGs) caused by CMV infection. A total of 138,336 unigenes were assembled, and 74,525 unigenes were annotated. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that the three major enrichment pathways (according to the p-values) were flavonoid biosynthesis, sulfur metabolism, and photosynthesis. Genes involved in basal defenses, probably R genes, were determined to be related to CMV resistance. Using quantitative real-time PCR, we validated the differential expression of 8 genes. A number of genes associated with CMV resistance were found in this study. This study provides transcriptomic information regarding CMV-Luffa spp. interactions and will shed light on our understanding of host-virus interactions.