Involvement of protein lysine acetylation in mediating grape berry ripening

• Protein lysine acetylation occurs extensively throughout grape berry development and ripening. • Increased protein lysine acetylation accelerates the ripening process of grape berries. • Genes encoding acetyltransferases and deacetylases potentially involved in grape berry ripening-associated protein acetylation were identified. • Exogenous ABA application enhances global protein lysine acetylation and accelerates grape berry ripening. Protein lysine acetylation is a dynamic post-translational modification crucial for regulating diverse biological processes in plants, yet its role in grape berry ripening remains largely unexplored. Here we investigate this role using the grape cultivar ‘Heicui’, whose skin colour dynamically reflects ripening progression. We demonstrate that global lysine acetylation occurs extensively during grape berry development and ripening. Treatment with an exogenous deacetylase inhibitor accelerates the grape berry ripening process. Using the grape reference genome, we identified eight genes encoding lysine acetyltransferases (VvKATs) and 14 encoding lysine deacetylases (VvKDACs). Expression profiling revealed that two VvKATs ( VvHAM1 and VvHAG3 ) and three VvKDACs ( VvHDT1, VvHDA19b and VvHDT2 ) are consistently highly expressed throughout berry development and ripening, suggesting their roles in maintaining dynamic protein acetylation levels. Additionally, exogenous abscisic acid (ABA) treatment promoted global lysine acetylation, and promoter analysis revealed that 12 of the 20 expressed VvKATs and VvKDACs harbour ABA-responsive cis -elements (ABREs), with seven exhibiting significant expression responses to exogenous ABA treatment. Finally, we discuss the potential molecular mechanisms underlying protein lysine acetylation-mediated and ABA-mediated grape berry ripening, as well as their causal relationship. Collectively, this study provides evidence that protein lysine acetylation plays a role in grape berry ripening, and advances our understanding of the physiological roles of non-histone protein acetylation in fruit ripening.