GSE39734
Genome-wide identi?cation of Vitis vinifera microRNAs reveals their differential regulation by gibberellin
MicroRNAs (miRNAs) play a important part in post-transcriptional gene regulation and have been shown to control many genes involved in various biological and metabolic processes.  There have been extensive studies to discover miRNAs and analyze their functions in model plant species, such as Arabidopsis and rice and other plants.  However, the number of miRNAs discovered in grape is relatively low and little is known about miRNAs responded gibberellin during fruit germination.  In this study, a small RNA library from gibberellin grape fruits was sequenced by the high throughput sequencing technology.  A total of 16,033,273 reads were obtained. 812,099 total reads representing 1726 unique sRNAs matched to known grape miRNAs. Further analysis confirmed a total of 149 conserved grapevine miRNA (Vv-miRNA) belonging to 27 Vv-miRNA families were validated, and 74 novel potential grapevine-specific miRNAs and 23 corresponding novel miRNAs* were discovered.  Twenty-seven (36.5%) of the novel miRNAs exhibited differential QRT-PCR expression profiles in different development gibberellin-treated grapevine berries that could further confirm their existence in grapevine.  QRT-PCR analysis on transcript abundance of 27 conserved miRNA family and the new candidate miRNAs revealed that most of them were differentially regulated by the gibberellin, with most conserved miRNA family and  26 miRNAs being specifically induced by gibberellin exposure.  All novel sequences had not been earlier described in other plant species.  In addition, 117 target genes for 29 novel miRNAs were successfully predicted.  Our results indicated that miRNA-mediated gene expression regulation is present in gibberellin-treated grape berries.  This study led to the confirmation of 101 known miRNAs and the discovery of 74 novel miRNAs in grapevine. Identification of miRNAs resulted in significant enrichment of the gibberellin of grapevine miRNAs and provided insights into miRNA regulation of genes expressed in grape berries. GSM604831 is the control for the gibberellin-treated sample. Overall design: The mixture samples of young berries (one week after flowering) large berries (five week after flowering after flowering), and old berries (nine week after flowering) treated with gibberellin, respectively, were generated by deep sequencing, in triplicate, using Illumina 1G Genome Analyzer.