Figure 5.

CsERF53 directly regulates the transcription of carotenogenic genes.

(A) A Y1H assay identified interactions of CsERF53 with the promoters of carotenogenic genes. PGADT7-Rec-p53+p53-AbAi and empty PGADT7+pAbAi-ProCBGs served as positive (P. Control) and negative (N. Control) controls, respectively. Aureobasidin A was the yeast cell growth inhibitor. SD/-Leu medium was supplemented with 200 ng mL⁻¹ Aureobasidin A (ProCsGGPPS and ProCsZEP) or 150 ng mL⁻¹ Aureobasidin A (ProCsHYD and ProNCED2).

(B–F) ChIP–PCR assays showed the interaction of CsERF53 with several regions in the promoters of carotenogenic genes. Cross-linked chromatin samples were extracted from GFP-CsERF53 fruit calli and precipitated with an anti-GFP antibody. The eluted DNA fragment was amplified by qPCR.

(G) Schematic representation of reporter and effector constructs used in the dual-luciferase assays.

(H) Dual-luciferase assays indicated that CsERF53 enhances the transcription of carotenogenic genes. ABA treatment (100 μM) in the dual-luciferase assay was performed for 1 day before determination. Data are presented as means ± SDs of three biological replicates. Asterisks indicate statistically significant differences determined by Student’s t test (∗p < 0.05; ∗∗p < 0.01; n.s., no significant difference).