ChIP-Seq Analysis of SlAREB1 Downstream Regulatory Network during Tomato Ripening

SlAREB1, a member of the abscisic acid (ABA) response element-binding factors (AREB/ABFs) family, was reported to play a crucial role in the expression of ABA-regulated downstream genes and affect the ripening of tomato fruit. However, the downstream genes ofSlAREB1are still unclear. Chromatin immunoprecipitation (ChIP) is a powerful tool and a standard method for studying the interactions between DNA and proteins at the genome-wide level. In the present study,SlAREB1was proved to continually increase until the mature green stage and then decrease during the ripening period, and a total of 972 gene peaks were identified downstream ofSlAREB1by ChIP-seq analysis, mainly located in the intergenic and promoter regions. Further gene ontology (GO) annotation analysis revealed that the target sequence ofSlAREB1was the most involved in biological function. Kyoto Encylopaedia of Genes and Genomes (KEGG) pathway analysis showed that the identified genes were mainly involved in the oxidative phosphorylation and photosynthesis pathways, and some of them were associated with tomato phytohormone synthesis, the cell wall, pigment, and the antioxidant characteristic of the fruit as well. Based on these results, an initial model ofSlAREB1regulation on tomato fruit ripening was constructed, which provided a theoretical basis for further exploring the effects of the regulation mechanism ofSlAREB1and ABA on tomato fruit ripening.Keywords:tomato;abscisic acid;SlAREB1transcription factor;ChIP-Seq;fruit ripening