Jasmonate (JA) critically regulates plant development and stress response, but its spatio-temporal distribution at the cellular level remains unclear. A JA biosensor consisting of a JA degron motif Jas9 fused with the fluorescent protein VENUS was developed in Arabidopsis (Larrieu et al., 2015), but its 35S promoter has low activity in reproductive tissues and does not express well in monocotyledons, thus limiting its application in crops and reproductive development.