Inhibition of ethylene‐induced cellular senescence symptoms by 1‐methylcyclopropene, a new inhibitor of ethylene action

Abstract

Ethylene is known to accelerate flower senescence, but the sequence of events that links its interaction with the tissue and the final senescence symptoms is still obscure. Recently, 1‐methylcyclopropene (1‐MCP) was found to inhibit ethylene‐induced wilting in flowers. This work was carried out in order to investigate the effects of 1‐MCP on cellular senescence symptoms in petunia flowers following expossure to ethylene. Cut petunia (Petunia hybrida) flowers that were exposed to ethylene for 12 h at concentrations of 1–12 ppm wilted sooner than their untreated counterparts. This effect was abolished by a 6‐h pre‐treatment with 1‐MCP. Immediately following the ethylene treatment, decreases in petal fresh weight and total protein content were measured, along with higher electrolyte leakage, and lower membrane lipid fluidity and protein content. When applied alone, 1‐MCP had relatively little impact on these parameters. However, when the flowers were treated with 1‐MCP prior to the ethylene treatment, ethylene had no effect. These results indicate that while ethylenes effects on wilting were obvious 3 days after the treatment, cellular parameters were affected already at the end of the treatment. Since 1‐MCP repressed these early ethylene effects, it was concluded that it interferes with ethylene action in petunia flowers at a rather early stage, long before apparent wilting.