Molecular mechanisms of abscisic acid on delaying postharvest physiological deterioration in cassava tuberous roots

Cassava ( Manihot esculenta Crantz) serves as a crucial food and energy crop with significant economic value. However, postharvest physiological deterioration (PPD) severely limits its shelf life and commercial potential. While abscisic acid (ABA) is known to affect the shelf life and quality of fruits, vegetables, and tubers after harvest, the proteomic and acetylproteomic mechanisms of ABA-induced PPD delay of cassava tuberous roots remain unknown. Herein, ABA was found to reduce H 2 O 2 content by enhancing the reactive oxygen species scavenging system. Integrated proteomic and acetylproteomic analyses identified 5721 proteins and 12,203 lysine acetylation sites. In total, 779, 169, and 1053 differentially expressed proteins (DEPs), along with 790, 235, and 931 differentially acetylated proteins (DAPs), were identified in the ABA48 vs. CK0, ABA48 vs. CK48, and CK48 vs. CK0 comparisons, respectively. Enrichment analysis revealed that DEPs or DAPs in ABA48/CK48 group were closely associated with antioxidant system and energy metabolism pathways, indicating major contributions of these pathways to cassava PPD. Transient silencing of MePrx2 resulted in significant increases in H 2 O 2 and malondialdehyde contents, suggesting MePrx2 acting as a key positive regulator in mitigating oxidative damage during PPD process. This study provides valuable insights into the regulation of ABA on delaying PPD at the protein abundance and acetylation levels, offering useful resources for extending shelf life of cassava tuberous roots.