Molecular and Physiological Assays of the Efficacy of 1-MCP at Preventing Adverse Ethylene Effects in Cotton.

The phytohormone ethylene can cause adverse effects in plants, including inhibition of shoot elongation and abscission of leaves, flowers and fruits.  1-MCP is a competitive inhibitor of ethylene binding with the ethylene receptors and prevents ethylene responses.  To determine the effectiveness of various 1-MCP delivery systems as an ethylene prophylactic, an assay system was developed that integrated analyses of leaf declination, shoot elongation and ethylene-responsive gene expression.  Using a flow-through controlled growth system, optimal parameters of ethylene treatment in eliciting responses, and of 1-MCP treatment in preventing these responses were determined.  A comparison was made between the effectiveness of gaseous 1-MCP delivery and liquid foliar application.  Data from global gene expression profiling analyses will be discussed.