Suppression of ethylene responses through application of 1-methylcyclopropene: A powerful tool for elucidating ripening and senescence mechanisms in climacteric and nonclimacteric fruits and vegetables

The discovery of l-methylcyclopropene (1-MCP) as an inhibitor of ethylene action has provided yet another effective tool for understanding the role of this hormone in the development of higher plants. In the nearly 12 years since the description of the effects of this growth regulator on ethylene action, the subsequent introduction of stable formulations has resulted in an explosive increase in 1-MCP-targeted research, particularly, although not exclusively, in the discipline of postharvest science. The vicinal relationship between 1-MCP and postharvest biology is understandable in view of the established roles of ethylene, both beneficial and detrimental, in the handling and storage behaviors of a vast majority of harvested fruit and vegetative organs. The use of 1-MCP is proving to be supplemental to molecular approaches for identifying and understanding the spectrum of senescence and ripening processes under the direct control of ethylene perception. Climacteric fruits have served as the predominant target for investigations of 1-MCP, and the responses of these fruits have confirmed that the antagonist operates in opposition to ethylene. Studies of nonclimacteric fruits challenged with 1-MCP and other ethylene action inhibitors have identified both ethylene-dependent and ethylene-independent ripening processes and have posed interesting questions regarding the canonical distinctions between climacteric and nonclimacteric fruits.