Pepper (Capsicum annuum L.) is a vital food commodity, and its shelf life plays a crucial role in determining economic viability. Ethylene, a key regulator in the ripening of climacteric fruits, such as peppers, considerably affects postharvest longevity. The ethylene biosynthesis pathway incurs management from gene families encoding 1-aminocyclopropane-1-carboxylate synthase (ACS) and 1-aminocyclopropane-1-carboxylate oxidase (ACO). The following study investigated the expression patterns of the ACS gene (CaACS6) and the ACO gene (CaACO1), along with a housekeeping gene (CaGAPDH), in three pepper cultivars (Cherry, Anaheim, and Bohemian), using quantitative polymerase chain reaction (qPCR). Gene expression assessment progressed across three maturity developmental stages (young green, large green, and ripening) to elucidate their influence on ethylene synthesis and pepper shelf life. The expression of the CaACS6 gene showed a positive correlation with the ripening stage across all cultivars. In the Cherry cultivar, the expression of gene CaACO1 significantly decreased at the ripening stage, indicating reduced ethylene production and potential for extended shelf life. Similarly, the Anaheim cultivar exhibited a decrease in the expression of both genes (CaACS6 and CaACO1) during the ripening stage, revealing a reduced ethylene production, suggesting a potential for reduced ethylene production and extended shelf life. These insights provide valuable guidance for selecting pepper cultivars with prolonged shelf life, thereby enhancing postharvest quality and commercial sustainability.

Keywords: Pepper (C. annuum L.), cultivars, CaACS6 and CaACO1, gene expression, ethylene production regulatory genes, maturity stages

Key findings: In pepper (C. annuum L.) cultivars, the gene CaACS6 expression with an increased ethylene biosynthesis at the ripening stage, confirmed its role in maturation. Reduced gene CaACO1 expression in pepper cultivars (Cherry and Anaheim) at the ripening stage suggested lower ethylene production, supporting their potential for extended shelf life.