Figure 2.

CsERF110 directly regulates the transcription of carotenogenic genes.

(A) A Y1H assay identified interactions of CsERF110 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, ProCsPDS, ProCsLCYB2, and ProCsLCYE) or 150 ng mL⁻¹ Aureobasidin A (ProCsCRTISO, ProCsHYD, and ProNCED2).

(B–I) ChIP–PCR assays showed the interaction of CsERF110 with several regions in the promoters of carotenogenic genes. Cross-linked chromatin samples were extracted from GFP-CsERF110 fruit calli and precipitated with an anti-GFP antibody. The eluted DNA fragment was amplified by qPCR.

(J) Dual-luciferase assays indicated that CsERF110 enhances the transcription of carotenogenic genes, and this enhancement is strengthened by ABA treatment. 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).