Expression analysis of 18 randomly selected RNA-Seq genes by qRT-PCR from PI 578718 (deep red bars) and PI 234881 (deep yellow bars). Green bars represented the different gene expression between two tall fescue genotypes. YT521-B gene was used as the reference gene for normalization of gene-expression data. Error bars represent the SE for three independent experiments, and three technical replicates were analysed. Bars with the same lower case letters within a treatment time level indicate are not significant differences; Bars with the same upper case letters within a genotype indicate not significant differences by Fisher’s least significant difference test at P < 0.05. CK, 12 h, and 36 h on the x-axis refer to control and 12 and 36 h after heat stress. Gene function and corresponding expression patterns extracted by RNA-Seq are listed in Additional file 6: Table S2.