Valeric acid delays aril breakdown of longan (Dimocarpus longan Lour.) fruit in relation to the regulation of histone deacetylase activity

Abstract

Aril breakdown results in the loss of nutrition and commodity value, thereby limits the postharvest storage of longan fruit. Histone deacetylases (HDACs) are important epigenetic regulators in many biological processes. Results in the current study showed that application of valeric acid (VA), which belongs to HDAC inhibitors, suppressed longan aril breakdown during postharvest storage. Meanwhile, lower contents of malondialdehyde, H2O2, and O2−., but higher activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione peroxidase (GPX) were observed in VA-treated fruit. Western blotting (WB) assay confirmed enhancement of histone H3 and H4 acetylation in VA-treated fruit, suggesting the possible inhibition of HDAC activity by VA. Furthermore, VA regulated DlHDACs expressions, with DlHDA5 and DlHDA8 expressions apposite of WB results. These results revealed that VA inhibited longan aril breakdown through enhancing the reactive oxygen species scavenging ability in relation to HDAC inhibitor activity. Our findings suggested that VA treatment delayed aril breakdown of longan fruit in relation to histone deacetylase-mediated epigenetic regulation and highlighted DlHDA5 and DlHDA8 potentially be important candidates for further research.