Retargeting a maize β-glucosidase to the vacuole - Evidence from intact plants that zeatin-O-glucoside is stored in the vacuole

► Plastid-localized Zm-p60.1 was successfully retargeted to the vacuole. ► Plants expressing Zm-p60.1 in the vacuole cannot store zeatin-O-glucoside. ► Vacuole-localized Zm-p60.1 restores zeatin-induced root-growth inhibition. ► The vacuole is the storage organelle for zeatin-O-glucoside. ► Zm-p60.1 is a robust probe for cytokinin metabolism in planta.