A glutathione S-transferase-activated fluorogenic sensor for in vivo plant stress diagnostics

Developing efficient tools to rapidly diagnose early plant stress becomes increasingly important due to the global food demand and the sustainable intensification of agriculture. Enzymes are highly associated with various environmental stresses in plants, some of which are considered biomarkers. Here, we report a new glutathione S -transferase (GST)-activated fluorogenic sensor (named as FPG ) for in vivo diagnostics of plant stress responses. The developed biosensor exhibits a good capability for in situ real-time fluorescence imaging of GST in living cells. More importantly, it enabled the direct visible, monitoring of plants subjected to various biotic and abiotic stresses in a non-invasive and non-destructive manner. Furthermore, FPG allowed the sensitive indication of fungal ( Sclerotinia sclerotiorum ) and viral (tobacco mosaic virus) diseases in Nicotiana benthamiana . Collectively, it reveals that the developed biosensor holds promise for the future development of high-throughput screening for plant phenotyping and the diagnosis of numerous environmental stresses.