Fig. 4: TOT3 regulates thermomorphogenesis independently from light signalling.

a–d Genetic interaction between 7-day-old tot3-2 and phyb-9 (a, b) (15 ≤ n ≤ 54) and pif4-101 (c, d) (18 ≤ n ≤ 53) at 21 and 28 °C under short-day conditions. Representative pictures (a, c) and hypocotyl length quantification (b, d). Scale bar, 5 mm (a, c). e Relative expression of temperature-responsive genes in 3-day-old Col-0 wild-type and tot3-2 seedlings in control (21 °C) and warm-temperature conditions (28 °C) under short-day conditions. f, g Genetic interaction between 3-day-old tot3-2 and pif4-101 at 21 and 28 °C in darkness. Representative pictures (f) and hypocotyl length quantification (g). Scale bar, 5 mm (f). h Relative expression of temperature-responsive genes in 3-day-old Col-0 wild-type and tot3-2 seedlings in control (21 °C) and warm-temperature conditions (28 °C) in darkness. Box plots show median with Tukey-based whiskers and outliers (b, d, g). The number of individually measured seedlings (n) is indicated above the X-axis (b, d, g). Bar diagram shows mean of 3 biological replicates (individual dots) with standard error of the mean (e, h). For the quantitative figures, letters indicate significant differences based on two-way ANOVA and Tukey’s test (p < 0.01) with fold-change between 21 and 28 °C being presented; n.s: not significant. The p-value for the interaction (genotype × temperature) is shown at the top.