Whole Genome Transcriptome Analysis of Grapevine Bud Dormancy

Bud dormancy is an integral component of growth cycling, productivity and winter survival in grapevines.  It has long been observed that development of dormancy requires vegetative maturation; however, vegetatively mature and floral competent grapevine buds can remain paradormant and resume growth when shoots are pruned or injured.   The object of this study was to identify and separate genes and molecular networks involved in vegetative maturation from those involved in endodormancy commitment processes. Bud endodormancy induction in Vitis riparia grapevines progresses from an early signaling and reversible transition phase to dormancy commitment phase in response to decreasing photoperiod.  A whole genome analysis, using NimbleGen grapevine microarrays, was used to identify endodormancy and paradormant specific gene expression profiles.  Age matched buds were analyzed during a three week period which resulted in endodormancy (short photoperiod, SD) or paradormancy maintenance (long photoperiod (LD).  There were over three times as many differentially expressed genes in endodormancy committed (SD) buds than in the vegetatively mature/paradormant (LD) buds.  Molecular network analysis and functional annotation provide identification of the distinct characters of endodormant and paradormant phases.