Expression pattern validation of selected genes by qRT-PCR. Expression changes of 21 DEGs in the salt-stressed calli relative to the control calli were measured by qRT-PCR. The transcriptional level of candidate genes was examined by real time PCR with three biological replications and actin was used as an internal control. Results were present as target/reference ratios normalized by the calibrator. No significant differences were shown between qRT-PCR and the Illumina data (Pearson’s correlation coefficient r = 0.8). The Y-axis indicates the fold change of transcript abundance in salt-stressed callus relative to the control callus. PeuC, P. euphratica control calli; PeuS, P. euphratica salt-stressed calli; PprC, P. pruinosa control calli; PprS, P. pruinosa salt-stressed calli.