|REID, MICHAEL - University Of California|
Submitted to: Horticultural Reviews
Publication Type: Literature Review
Publication Acceptance Date: 11/1/2011
Publication Date: 10/1/2012
Publication URL: http://media.wiley.com/product_data/excerpt/35/11183458/1118345835-104.pdf
Citation: Reid, M.S., Jiang, C. 2012. Postharvest biology and technology of ornamentals. In: Janek, J.,editor. Horticultural Reviews. Vol. 40. 1st edition. Hoboken, NJ:John Wiley & Sons, Inc., pp. 1-54.
Technical Abstract: The relatively brief postharvest life of most cut flowers and potted flowering plants can be extended by a range of technologies. Studies have shown that vase life is negatively correlated with respiration after harvest, so prompt cooling to the lowest safe storage temperature is a key to long-distance transport of these perishable crops. Forced air cooling is the method of choice for cut flowers, and vacuum cooling has been shown to be very effective for cooling potted plants. In contrast to some other horticultural crops, controlled and modified atmospheres seem to have little effect on petal respiration, and these techniques have not proved commercially useful in the marketing of many cut flowers. Low temperatures are also important in managing the effect of other factors contributing to early senescence, including water loss, the effects of ethylene, leaf yellowing and the growth of diseases, particularly Botrytis cinerea. Chemical strategies to reduce the effects of these factors include application of Abscisic acid, the volatile ethylene inhibitor 1-MCP, artificial cytokinins, and treatment with hypochlorite, respectively. Floral senescence is an active process with many of the hallmarks of programmed cell death. Molecular analysis has revealed a large number of candidate genes with possible roles in senescence and remobilization. Virus-induced gene silencing has been used to evaluate the potential role of some of these genes, particularly regulatory genes such as transcription factors and kinases. Ornamentals are particularly suited to testing transgenic strategies for extending shelf-life, and we report results of experiments using constructs containing inducible promoters to drive genes that extend flower life. Of particular interest is the dramatic extension of longevity resulting from silencing a component of the 26S proteasome which indicates the importance of targeted protein degradation in control of floral senescence, and could serve as a strategy for extending the life of ethylene-insensitive ephemeral flowers.