Tracking Myrosinase Regulation across Multiscale Interactions with Fluorescent Glucosinolates

The conversion of glucosinolates (GSLs) into chemopreventive isothiocyanates (ITCs) primarily relies on plant myrosinase (MYR) or specific bacteria. MYR dynamics are deeply involved in plant defense systems, gut microbiota metabolism, and complex interactions and regulation across species. A set of activity-based probes was developed to track MYR in vivo by biomimicking natural GSL with robust sensitivity and selectivity. The dynamics and heterogeneous distribution of MYR in distinct sections and species were captured via fluorescence imaging of live plants. Specifically, under herbivore challenge to leaves, a systemic, long-distance upregulation of MYR activity in root tissues has confirmed cross-species MYR regulation in plant defense. Furthermore, for the first time, quantitative visualization of the dynamic metabolic competition of GSL and sugar has confirmed the metabolic priority of sugar in gut microbiota and colonized zebrafish in vivo. The competitive metabolism is involved in the crosstalk during cross-species microbes and host-microbe interactions. Tracking MYR regulation across species by the designed probes has offered rich insights into the dynamic interplay among diet, microbiota, and host health.