Scientists finding ways to extend flower shelf life

Scientists at the Univ. of Calif.-Davis are investigating a number of practical methods for controlling plant senescence in order to extend the shelf life of fresh cut flowers and flowering potted plants.
One study involved the spraying of low concentrations of thidiazuron (TDZ) to extend the life of leaves and flowers on potted plants. TDZ is a synthetic version of the naturally occurring plant hormone cytokinin. TDZ-treated greenhouse-grown cyclamen plants lasted a month longer than untreated plants. Plants that received 5-10 ppm TDZ sprays did not show any phytotoxic response to the treatments.
Further studies with TDZ aim to determine why some potted plants are nonresponsive to TDZ treatment. For example, the chemical maintains the freshness of some kinds of miniature potted roses, but not others.
In other research, the scientists are studying virus-induced gene silencing to determine the function of genes in plant senescence. By incorporating gene modification, the scientists are looking to determine the genes involved in producing ethylene, which causes senescence. Using the virus technique the scientists are looking to be able to turn off genes to determine which ones control senescence.