Molecular reprogramming in grapevine woody tissues at bud burst

Perennial woody plants undergo a period of dormancy from the beginning of autumn until the end of spring. Whereas the molecular and physiological events that characterize dormancy release of buds have been described in detail, those occurring in woody tissues underneath the buds are mostly unknown. To bridge this gap, the mRNA populations of cane segments located underneath the bud were analyzed at bud dormancy (E-L 1) and at bud burst (E-L 4). They revealed an important reprogramming of gene expression suggesting that cell division, cell wall metabolism and the mobilization of sugars are the main metabolic and cellular events occurring in cane woody tissues at bud burst. Also, the upregulation of several genes of sugar metabolism, encoding starch- and sucrose-degrading enzymes and sugar transporters, correlates with the decrease in starch and soluble sugars in woody tissues concomitant with increased sucrose synthase and -amylolytic biochemical activities. The latter is likely due to the VviAMY2 gene that encodes a functional -amylase as observed after its heterologous expression in yeast. Taken together, these results are consistent with starch and sugar mobilization in canes being primarily involved in grapevine secondary growth initiation and supporting the growth of the emerging bud.
FCT—Portuguese Foundation for Science and Technology, under the strategic programs UID/AGR/04033/2019 and UID/BIA/04050/2019. The work was also supported by FCT and European Funds (FEDER/POCI/COMPETE2020) through the research projects MitiVineDrought (PTDC/BIA-FBT/30341/2017 and POCI-01-0145-FEDER-030341), BerryPlastid (PTDC/BIA-FBT/28165/2017 and POCI-01-0145-FEDER-028165) and AgrifoodXXI (NORTE-01-0145-FEDER-000041). AS was supported by an FCT PhD grant (SFRH/BD/135782/2018). HN was supported by an FCT postdoctoral grant (SFRH/BPD/115518/2016). This work also benefited from the networking activities within the European funded COST ACTION CA17111 INTEGRAPE. We are grateful to the genotoul bioinformatics platform (Toulouse, France) for providing help for computing and storage ressources. The authors wish to thank Pr. Zhanwu Dai (present address: Institute of Botany Beijing, Chinese Academy of Sciences, Beijing) for his input in the initial stages of this work
info:eu-repo/semantics/publishedVersion