Plant phosphorus(P)diagnosis is widely used for monitoring P status and guiding P fertilizer application in field conditions.The common methods for predicting plant response to P are time-and labor-consuming chemical measurements of the extractable soil P and plant P concentrations.In this study,we successfully generated a visual reporter system in tobacco(Nicotiana tabacum L.)to monitor plant P status by expressing a Purple gene(Pr)driven by the promoter(Pro)of OsPT6,a P-starvation-induced rice gene.