Transcriptome profile analysis reveals the ontogenesis of rooted chichi in Ginkgo biloba L.

The Ginkgo biloba L. chichi is a unique organ. To explore the molecular mechanisms underlying the ontogenesis of G. biloba chichi, we used RNA-seq to analyse the transcriptome profile of rooted chichi at two developmental stages (ch1 and ch2) and nearby tissues (ck), and each sample had three biological replicates. A total of 57.74 Gb of clean bases were generated in nine cDNA libraries. These bases were de novo assembled into 68,277 unigenes with average length of 844 bp, and 51.47% of the unigenes had a match in at least one public database. The differentially expressed genes (DEGs) in chl vs. ck and ch2 vs. ck were 2748 and 8594, respectively. The DEGs involved in the auxin signal pathway, auxin polar transport, storage-related proteins, and the cell cycle pathway might play roles in the ontogenesis of chichi. The quantitative real-time PCR results were closely correlated with transcriptome data. The transcriptome resources generated in the current study provide gene expression profiles and differential expression profiles of G. biloba chichi and offer an essential resource to probe the molecular mechanisms underlying the ontogenesis of G. biloba chichi.