## 5 Conclusions  
This manuscript provides an in-depth, comprehensive overview of the biochemical and molecular effects of inactivated dry yeast extracts (DYE) on white grapes (var. Sauvignon Blanc). Our results demonstrated that DYE treatment did not interfere with the overall berry ripening process, as it did not affect sugars or acidity. Its action was, instead, more specifically and effectively directed towards selected metabolic and hormonal pathways. Specific aroma precursors, especially those related to sulphur and GSH metabolism, cys-3 MH and GSH-3 MH, typically contributing to Sauvignon Blanc aroma, were found at higher levels in grapes from vines sprayed with the DYE. Furthermore, the complete profile of amino acids as well as the RNA-seq transcriptional profiles strongly indicated that the treatment with DYE was able to trigger an unequivocal \"priming\" effect on berries by affecting the ROS balance and reducing oxidative damage, thus improving the stress tolerance, particularly heat stress. The DYE also stimulated a subset of ethylene and JA responses while interfering with some ABA and auxin-related genes, an aspect that will need further characterization for its functional relationships with the activation of stress responses exerted by the DYE.  
**Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/plants12193423/s1](https://www.mdpi.com/article/10.3390/plants12193423/s1)]([https://www.mdpi.com/article/10.3390/plants12193423/s1](https://www.mdpi.com/article/10.3390/plants12193423/s1)), Table S1: Amino acids and glutathione determined in samples from 2020 and 2021. Table S2: Free aroma precursors (ug/kg) determined at all time points in samples collected in 2020. Table S3: Bound aroma precursors (ug/kg) quantitated at harvest in the two years 2020 and 2021. Table S4: Targeted approach (RT-qPCR) on berries collected from both years to reach a first molecular characterization of the samples. Table S5: Untargeted molecular responses of DYE-treated versus untreated berries at TP2 and harvest in 2020. Arabidopsis function obtained from NCBI. Figure S1: Meteorological data (air temperature and rainfall) in 2020 and 2021 in Sequals, Friuli-Venezia Giulia, Italy.  
**Author Contributions:** Conceptualization, M.R., S.Q., M.M., D.P., C.B., F.B. and B.R.; methodology, M.R., P.H., R.B., A.R., V.C., P.C., S.B., D.P. and B.R.; software, M.R., C.F., L.R. and F.M.; data curation, M.R., C.F., L.R., P.H., F.M. and B.R.; writing--original draft, M.R. and B.R.; writing--review and editing, M.R., P.H., S.Q., C.B. and B.R.; supervision, B.R.; funding acquisition, F.B. and B.R. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by Lallemand Italia (Italy)--Danstar Ferment AG (Switzerland) project RUPE_COMM21_01. M.R. was supported by a PhD grant from \"Fondazione Cassa di Risparmio di Padova e Rovigo\"--cycle 36.  
**Data Availability Statement:** The datasets generated during and/or analyzed during the current study are listed in the text and its additional files.  
**Acknowledgments:** The authors would like to thank the company managing the vineyard where the experiments were performed: Azienda Agricola La Madunina, Sequals, Italy.  
**Conflicts of Interest:** This research was partially funded by Lallemand Italia, responsible for the development and commercialization of the DYE product \"LalVigne(tm) AROMA\" used in the experiments.