Project Number: 5306-13210-001-02
Project Type: Specific Cooperative Agreement

Start Date: Dec 15, 2006
End Date: Jul 31, 2009

Objective:
1. Determine flower freshness during postharvest handling. 2. Development of a freshness index. 3. Identification and characterization of senescence-associated genes/promoters: a) Isolation of gene specific promoters; b) Targeted regulation of senescence-associated genes; c) Targeted inihibition of protein synthesis.

Approach:
1) Freshly cut flowers of different species (at least two cultivars for each species) will held at different temperatures, and their respiration rate will be determined. 2) From a pre-existing database of genes whose expression changes during petal senscence in daylily, four o'clocks, and daffodils, as well as published databases on iris, carnation, and petunia we will identify genes whose expression pattern suggests an association with senescence. 3a) Using EST collections we will identify genes whose expression changes dramatically in the early stages of floral senescence. 3b) Transgenic petunia plants will be generated using standard techniques, and the life of the flowers from the transformed plants will be compared with that of control plants. 3c) Transform petunia with constructs combining floral senesence-specific promoters with genes encoding proteins known to interfere with ribosome function. Documents SCA with UC Davis.