Team:UNITN-Trento/Project/Datapage

We envision the construction of a genetic circuit that either produces ethylene or methyl-salicylate (MeSA) in response to either the presence or absence of light. In the dark state the sensor protein YF-1 first auto-phosphorylates and then phosphorylates the response regulator FixJ. Phosphorylated FixJ is then able to bind to the pFixK2 promoter thereby activating transcription of cI (the inhibitor protein) that ultimately blocks EFE production. At the same time, phosphorylated FixJ activates the transcription of Bmst1, which initiates the synthesis of MeSA, thus slowing down fruit ripening.

In the presence of blue-light, the sensor protein YF-1 does not auto-phosphorylate and does not phosphorylate FixJ. The RNA polymerase does not recognize the pFixK2 promoter. The result is that ethylene is produced and MeSA synthesis is blocked. In other words, fruit ripening is induced.