Gibberellin and shikimic acid modulate cell wall metabolism to attenuate postharvest softening in jujube fruit

Fruit softening constitutes the critical factor governing both shelf life and storage quality in fresh jujube. Our study systematically evaluated the effects of exogenous gibberellin (GA 3 ) and shikimic acid (ShA) on postharvest quality parameters in jujube, with particular focus on firmness retention and cell wall metabolism dynamics. We showed that the two different treatments significantly delayed the fruit firmness decline and reduced the weight loss rate. Besides, compared with control fruit, the treated jujube displayed significantly higher levels of PP and CEL while lower WSP content, and GA 3 and ShA significantly suppressed the activity of key cell wall-degrading enzymes, including polygalacturonase (PG), pectin methylesterase (PME), cellulase (CL), and β-galactosidase (β-Gal), concurrently downregulating their corresponding gene expression. Notably, ShA treatment significantly elevated both GA 3 and ShA levels in the fruit, whereas GA 3 treatment only marginally affected ShA content, suggesting that ShA may influence fruit softening through modulating GA metabolism. Additionally, correlation analysis suggests that ZjPG1 , ZjPME2 , ZjGal1 , ZjCL1 , and ZjCL3 are likely to be the candidate genes contributing to the postharvest fruit softening of fresh jujube. • Both GA 3 and ShA treatments delay the softening of postharvest ‘Dongzao’ fruit. • Applying GA 3 and ShA inhibits the degradation of protopectin and cellulose. • Cell wall-degrading enzyme activity was significantly inhibited in treated fruit. • Both two treatments suppress transcription of key cell wall-degrading enzyme genes. • ShA may affect fruit softening by participating in GA metabolism.