Fig. 10

Gene expression analysis of lettuce Hsf and Hsp genes under different light conditions. a Schematic representation of the experimental design used at different light treatment on lettuce plants. L. sativa cultivar Codex plants were grown under light 150 μmol·m^− 2·s^− 1 for 10 days then 220 μmol·m^− 2·s^− 1 was treated for 22 days. Control light (μmol·m^− 2·s^− 1), UV light (11 μmol·m^− 2·s^− 1 supplemented with 220 μmol·m^− 2·s^− 1 of white light), and high intensity light (440 μmol·m^− 2·s^− 1) were imposed to lettuce plants for 4 days. b Physical appearance of L. sativa cultivar “Codex” 4 days after treatment with control light (CT), UV, and high intensity light (HL). c The relative expression of lettuce Hsf and Hsp genes. mRNA levels were determined by RT-qPCR analysis and normalized to that of LsTUB. log₂FC (fold change) values of relative expression of treatment (UV and HL) to the control (CT) are presented. Asterisks indicate significant differences between treatment and control determined by Wilcoxon’s singed-rank test (* p < 0.05, ** p < 0.01, *** p < 0.001). Genes marked with the same letter (a-f) represent segmentally duplicated genes; genes marked with the same number (1–5) belong to the same tandem duplicated gene cluster