Transcriptome profiling reveals regulatory mechanisms underlying corolla senescence in petunia

Flower development: When to wilt How long flowers bloom is determined by genes that alter levels of the plant hormones ethylene and auxin. When flowers are no longer needed, plants signal them to die; the underlying genetic mechanisms are not well understood. Cai-Zhong Jiang at the University of California, Davis and co-workers used genetic analysis to determine how the signals for petal death are encoded. They studied petunia flowers at four stages: opening, pollen release, onset of wilting, and fully wilted, and identified over 5000 genes that were turned up or down. The master switches for petal death were found to be genes controlling ethylene and auxin levels. Using a virus to artificially switch off several genes, the researchers identified genes that shorten or extend flower life by up to three days. These results may be useful in plant breeding