Comparative transcriptome analysis of differentially expressed genes between the curly and normal leaves of Cymbidium goeringii var. longibracteatum

Normal and the spontaneous spirally rolled leaves of Cymbidium goeringii var. longibracteatum were used for RNA sequencing analyses using the Illumina paired-end sequencing technique to figure out the differently-expressed genes in two samples. About 5.65 and 4.82 Gb sequencing data of raw reads were obtained from 2 cDNA libraries of normal and the spirally rolled leaves respectively. After data filtering, quality checks and de novo assembly, a total of 48,935 unigenes with an average sequence length of 820 nt were generated. In addition, the transcriptome change in normal and the spirally rolled leaves was investigated. With non-redundant annotation, 219 differentially expressed genes (DEGs) are identified, with 147 up-regulated genes and 72 down-regulated genes. Out of these DEGs, 21 DEGs (9.59 %) were involved in cell wall modeling enzymes, such as expansin, xyloglucan endo-transglycosylase, pectate lyase, cell wall-associated hydrolase. Besides, other DEGs were predominantly classified as genes involved in transcription factor and signal sense and transduction signaling. This study presents the first comprehensive characterization of the leave transcriptomes of Cymbidium goeringii var. longibracteatum. This study not only gave us valuable sequence resources of this species, but also provided theoretical foundation for cultivar breeding of leaf mutation in C. goeringii var. longibracteatum.