Fig. 5
REF6 and HSFA2 form a regulatory loop that is maternally transmitted. a EMSA shows that His-HSFA2 protein but not His by itself specifically binds to the first HSE (nTTCnnGAAn motif) of REF6 promoter in vitro. Arrows indicated the shifted bands. Excess unlabeled probe could outcompete the labeled probe (middle). A mutant HSE and a REF6-NC sequence were used as negative controls (right).The motif is highlighted in red in the probe. The region validated by ChIP-qPCR in b was marked by a bar. b ChIP-qPCR validation of HSFA2 occupancy at the REF6 promoter region. The data were normalized to the corresponding input fraction. The REF6-NC locus was used as the negative-control locus. c REF6 transcript level in 24-day-old Col and hsfa2 grown at 22 °C and 30 °C. d The progeny derived from crosses (F1) of Col 30 °C♀×Col 22 °C♂ but not Col 22 °C♀×Col 30 °C♂flowered earlier. Flowering time of different lines was assessed by counting leaf numbers in bolting plants (n ≥ 15 for each line). e Lower H3K27me3 levels of HSFA2 persisted in the progeny derived from Col 30 °C♀×Col 22 °C♂but not Col 22 °C♀×Col 30 °C♂. Data were shown as means ± SD from three replicates (b, c, e). Lowercase letters indicate statistical significance based on one-way (b, d, e) or two-way (c) ANOVA with Tukey’s HSD post hoc analysis (P < 0.05)
