(E) The PSR activates RALF expression in a PHR1-dependent manner. Col-0 and phr1 seedlings were grown in LP media for 5 days and roots were harvested. The relative expression of RALFs was quantified via RT-qPCR. The data shown indicate the means ± SDs (n = 3, n refers to technical replicates); n.s., not significant; **, p < 0.01 (Student's t test). Data information: All experiments were repeated three times with similar results. 