We envision this genetic circuit in which production of ethylene and methyl-salycilate (MeSA) are regulated by light. In a dark state, the sensor protein YF-1 auto-phosphorilates itself, dimerize, and transfer the phosphate to the response regulator element FixJ. FixJ is so activated and is able to bind pFixK2 promoter, activating transcription of cI (inhibitor protein) that ultimately blocks EFE production. At the same time, it is transcribed Bmst1, which regulates MeSA synthesis thus slowing down fruit ripening. In a blue-light state the sensor protein YF-1 does not phosphorilate itself, so pFixK2 promoters is in the off state: ethylene is produced thus promoting ripening while MeSA production is blocked.