## 3 Results
### Regulatory Mechanism of Hormones on Anthocyanin Synthesis
ABA and MeJA significantly upregulated the expression levels of VvmiR156b/c/d and anthocyanin structural genes in the early stage of color conversion (7 DAT and 14 DAT), and ABA and MeJA are mainly involved in the formation of color in the early color-change period. NAA treatment downregulated the expression of VvmiR156b/c/d and anthocyanin structural genes; NAA delayed the peak expression of genes to 35 DAT and is mainly involved in the formation of color in the mature stage. Thus, we conclude that VvmiR156b/c/d-_VvSPL9_ can respond to different hormone signals to participate in the formation of anthocyanin of different periods (Figure 9), but the mechanism of the hormone signaling pathway remains unclear. At present, a variety of miRNA has been proved to be involved in the response and synthesis of plant hormones. miR167 affects the development of pistils, stamens, and petals of Arabidopsis thaliana by regulating the expression of ARF6 and ARF8 [51], and miR60 affects the formation of root cap cells by regulating the expression of ARF10 and ARF16 [52]. DELLA, the key molecule of gibberellin signal transmission, has a direct protein interaction with the target gene SPL of miR156. Gibberellin is regulated by the transcription factor of the target gene SPL of miR156 [53]. More interestingly, miR159 appears in many plant hormones signaling pathways. It can be up-regulated by the regulation of GA and ABA [54; 55], and it will be down-regulated by the regulation of ethylene [56]. There are various kinds of miRNAs, and with the discovery of new miRNAs in different species, there is still a long way to go to clarify the relationship between miRNAs and plant hormones. Figure 9: The network of anthocyanins regulated by VvmiR156b/c/d-_VvSPL9_ responds to hormones. **Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/foods10040896/s1](https://www.mdpi.com/article/10.3390/foods10040896/s1)]([https://www.mdpi.com/article/10.3390/foods10040896/s1](https://www.mdpi.com/article/10.3390/foods10040896/s1)), Table S1: The cloning primers of VvmiR156b/c/d and _VvSPL9_; Table S2: The cloning primers of VvmiR156b/c/d and _VvSPL9_ promoters; Table S3: Quantitative primers of VvmiR156b/c/d and _VvSPL9_; Table S4: Quantitative primers for anthocyanin synthesis genes of grape; Table S5: Quantitative primers for anthocyanin synthesis genes of tomato; Table S6: Volatile substances in 'Wink'; Table S7: Classification and functional analysis of the promoter of VvmiR156b/c/d; Figure S1: HPLC chromatogram of anthocyanins standard sample (cyanidin-3-O-glucose chloride); Figure S2: GC-MS chromatogram of 'Wink' berry flesh; Figure S3: The correlation analysis of VvmiR156b/c/d-_VvSPL9_ and anthocyanin synthesis-related genes in response to hormone signals. **Author Contributions:** [PERSON] conceived the entire research and designed the experiment. [PERSON]. ([PERSON]), [PERSON], [PERSON], [PERSON] ([PERSON]), [PERSON], [PERSON] and [PERSON] performed the experiments and the analyzed data. [PERSON]. ([PERSON]) drafted the manuscript. [PERSON], [PERSON] and [PERSON] revised the paper. All authors have read and approved the final manuscript. **Funding:** This study was financially supported by the National Key Research and Development Program of China (2018 YFD1000106), the National Natural Science Funds (31972373; 31872047; 31801809), the Special Program for Training College Students in Innovative Entrepreneurship (S20190012), and the Jiangsu Province Natural Science Funds (BK20181318). **Data Availability Statement:** Data is contained within the article or Supplementary Materials. **Acknowledgments:** We would like to express our gratitude to the Jiangsu Academy of Agricultural Sciences for providing the grape material. We thank [PERSON] from the State Key Laboratory of Crop Genetics & Germplasm Enhancement for helping with the analysis of the GC-MS data. **Conflicts of Interest:** The authors declare no conflict of interest.