Silencing of a Proteasome Component Delays Floral Senescence

Targeted protein degradation via the ubiquitin/26S proteasome pathway is known to play an important function in many phases of plant growth and development.  In previous research we demonstrated that silencing a putative E3 ubiquitin ligase (a component of the pathway) delayed floral senescence.  To further test the function of targeted protein degradation in flower senescence, we chose to silence an endopeptidase component in the 20S core of the 26S proteasome.  Petunia hybrida was transformed with a construct allowing for chemically-inducible silencing of this protein.  Flowers from transgenic plants treated with the chemical inducer showed doubled vaselife than controls (transgenic flowers held in water).  These results indicate that targeted protein degradation plays an important regulatory role in floral senescence.