Effect of sound wave treatments on the expression of hormone-related genes in Arabidopsis roots. qRT-PCR was used to determine the expression levels of genes related to cytokinin ((A), AHKs; (B), ARRs), auxin ((D), PINs; (E), AtAUX1, AtLAX2, and AtLAX3), and ethylene ((F), AtEIL1, AtEIN2, AtEIN3, AtERF1, and AtPIF4) pathways, as well as AtSHY2 (C). The values were normalized to the value of the control. qRT-PCR error bars indicate the standard error of the mean of three biological replicates. Different letters above the bars indicate significantly different mean values (p < 0.05) based on Duncan’s multiple range test.