Comparative Transcriptome Analysis Provides Insight into Differentially Expressed Genes Related to Bud Dormancy in Grapevine (vitis Vinifera)

Bud dormancy is an important adaptive strategy of perennial woody plants that benefits survival of a species under unfavorable conditions. Grapevine is one of the most important fruit species with wide distribution all over the world. There are two kind of buds, latent buds and prompt buds, along shoots of grapevine, which show different phenotypes in terms of dormancy. To better understand the molecular mechanisms behind this, the transcriptomes of grapevine (Vitis vinifera) latent buds and prompt buds were analyzed using RNA-sequencing (RNA-seq) technology and compared. Of all the genes detected, 4864 were identified as differentially expressed genes (DEGs), with 2613 being upregulated and 2251 being downregulated in latent buds than in prompt buds. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that these DEGs were mostly associated with biological process, single-organism transport, lipid metabolic process and transporter activity, and also involved in biosynthesis of secondary metabolites, metabolism of phytohormone, flavonoids, phenylpropanoid, sugar and fatty acid. Lots of transcription factors (TFs), especially some members of MTh, TCP, and DAM, were identified to be candidates regulating grapevine bud dormancy. Results of transcriptome profiling were validated using real-time PCR in 27 selected genes. The results revealed that interactions of phytohormone, sugars and flavonoids and their regulation to the cell-cycle genes via the mediation of TFs may contribute greatly to grapevine bud dormancy. Consequently, this study provides abundant genetic resources and lays a foundation for further research on the molecular mechanisms underlying bud dormancy in grapevine.