658 Engineering Ethylene Synthesis and Perception for Fun and Profit

Abstract

Ethylene-based technologies for controlling ripening in climacteric fruit have been in widespread use for a number of years. Likewise, using chemicals that block ethylene synthesis or perception have been widely used to extend shelf life of a variety of horticultural commodities. In the last few years, our understanding of the molecular mechanisms for ethylene synthesis and perception has greatly expanded. Genes encoding the ethylene biosynthetic enzymes and the ethylene receptor have been cloned from many plant species, which has meant that molecular approaches to engineering reduced ethylene synthesis or perception are now reality. Scientists have been examining the feasibility of using molecular approaches to control ethylene in a variety of horticultural and ornamental species. They have shown that it is relatively easy to produce plants that are reduced in either synthesis or response to ethylene. However, scientists have uncovered some issues associated with commercial-level use of these transgenic plants. Overall, my results illustrate the great potential of the technology to control the rate of climacteric fruit ripening, abscission, and ethylene-induced senescence in multiple species, but using transgenes in many cases needs to be directed to target tissues through the use of tissue-specific transcriptional promoters. With that caveat in mind, there should be a strong future for improving the quality of a range of agronomic and horticultural species.