Integrative multi-omics analysis unravels chitosan-mediated delay of mango fruit ripening through hormonal and...

Mango (Mangifera indica L.), a climacteric fruit of significant global economic value, suffers from rapid postharvest deterioration driven by complex hormonal and transcriptional networks. While chitosan coating is known to extend mango shelf-life, the precise molecular mechanisms, particularly its interplay with key ripening hormones like abscisic acid and ethylene, and the role of transcriptional regulators, remain poorly understood. We hypothesized that chitosan delays ripening by reprogramming abscisic acid and ethylene signaling pathways and associated transcriptional networks. To test this, we employed an integrative multi-omics approach combining transcriptomics and metabolomics to elucidate the molecular basis of chitosan-mediated ripening delay in mango fruit. Our findings reveal that chitosan orchestrates a dual hormonal attenuation associated with suppression of abscisic acid biosynthesis (NCED3, ABA2) and ethylene signaling (ETR1, EIN3/EIN4) while enhancing abscisic acid catabolism (CYP707A1/4). Crucially, γ-aminobutyric acid (GABA) accumulation antagonized abscisic acid to uncouple starch-to-sugar conversion from ripening progression, correlating with retained firmness and chlorophyll levels. Furthermore, we identified key transcription factors, WRKY53 and bZIP/RF2b, likely acts as central hubs modulating abscisic acid-ethylene crosstalk and cell wall integrity. This knowledge provides novel mechanistic insights into chitosan action and offers a foundation for developing targeted strategies to optimize postharvest preservation in climacteric fruits by synchronously modulating Abscisic acid-ethylene crosstalk, GABA-mediated metabolic reprogramming, and key TFs.