Improving the ripening process after 1-MCP application: Implications and strategies

Background: Consumers' lifestyles demand high-quality products, requesting adequate fruit storage. Management of ethylene production is of paramount importance when planning postharvest storage, since this phytohormone is the key molecule behind the ripening and senescence process. Cold storage combined with 1-MCP has been one of the most applied postharvest treatments to extend the shelf-life of several fruit. However, 1-MCP is a potent inhibitor of ethylene action, leading frequently to the blockage of ripening denominated as 'evergreen' effect. Scope and approach: Ethylene biosynthesis and perception pathway are described, as well as a critical review on 1-MCP inhibitory mechanisms. Technologies used to induce postharvest ripening after 1-MCP application are described with special attention to the latest and most significant published works. The most relevant 1-MCP reversion strategies are discussed, aiming to develop more innovative and effective approaches for stimulating ripening. Finally, the importance of tailoring treatments to specific cultivars is discussed, using pear as a case study. Key findings and conclusions: Optimizing temperature and applying exogenous ethylene have been the main methods to reverse the effect of 1-MCP. Also, treatment with other phytohormones has shown promising results. However, the strategies effectiveness is dependent on the cultivar, time of application, and concentration of the applied compound. Also, since 1-MCP binds irreversibly to the ethylene receptor, the biosynthesis of new receptors may reverse the 'evergreen' behaviour. Therefore, attempts should be made to develop strategies according to each cultivar and their capacity to stimulate the expression of ethylene genes both related to its biosynthesis and perception.