Relative expressions of PpyCBFs and PpyCORs during abiotic stresses and exogenous abscisic acid (ABA). (a) Expression analysis of PpyCBFs during abiotic stresses (cold, salt, and drought) and ABA according to their phylogenetic clades. (b) Expression analysis of PpyCOR47, 15A, RD29A, and KIN in the same samples for comparison study. Both relative expressions were normalized to PpyActin expression level. Error bars indicate standard errors from three biological replicates (* p < 0.05, ** p < 0.01, *** p < 0.001) while means with different letters had significant differences (p < 0.05).