Controlled atmosphere storage modulates the exocarp-color and mesocarp-softening synchronization in ´Hass´ avocado

Controlled atmosphere storage is a key postharvest technology for extending the commercial life of ´Hass´ avocado ( Persea americana Mill.) during long distance transport. However, color-firmness desynchronization, where the mesocarp softens before the exocarp develops its characteristic black color, remains a major challenge. This study evaluated the combined effects of harvest maturity (middle and late) and storage conditions (regular air, RA; controlled atmosphere, CA) on exocarp color-mesocarp firmness synchronization in ´Hass´ avocado. Integrative transcriptomic and metabolomic analyses were performed on exocarp tissues collected after 30 days of storage and at the ready-to-eat (RTE) stage. Integrative multi-omics (DIABLO s PLS-DA) identified early candidate biomarkers of storage response, including WRKY22 , INT2 , SnRK2.10 , and arabitol (CA markers), and TT7/CYP75B1 , SUS4 , myo-inositol, and sucrose (RA markers). At the RTE stage, SLP2 , BOB1 , and SULTR3;1 correlated with black coloration, whereas MAPKKK21 , RPL24A , and IAA13 were associated with green phenotypes. Overall, CA storage maintained cellular homeostasis and promoted anthocyanin biosynthesis, leading to improved exocarp color–mesocarp firmness synchronization. These findings provide molecular and metabolic insights into the mechanisms underlying ripening uniformity in ´Hass´ avocado and propose potential biomarkers for early postharvest prediction of the disorder. • Controlled atmosphere (CA) improves exocarp-mesocarp ripening synchronization. • Regular air activates stress pathways bypassing precursors toward anthocyanin pathway. • WRKY22 , RnRK2.10 and arabitol emerge as early CA response biomarkers. • SLP2 , BOB1 and SULTR3.1 are correlated with black fruit at RTE stage.