Genome-wide identification of the histone acetyltransferase gene family in Citrus clementina and its potential roles in citrate metabolism

Abstract

Abstract Histone acetyltransferase (HAT) catalyzes histone acetylation and is involved in plant growth and development and stress responses. Here, 37 CitHAT genes were identified in Citrus clementina. Their physicochemical properties, chromosomal location, gene structure, conserved domain and motif, and cis-acting elements were characterized. CitHATs were classified into four subfamilies, HAG (32), HAC (2), HAF (2), and HAM (1), based on protein sequence homology, which was strongly supported by gene structure, conserved domain, and motif analysis. The cis-acting elements in gene promoter regions were predicted to be associated with the regulation of plant growth, stress resistance, and response to hormones. We further treated citrus callus with HAT inhibitor, the result showed that HAT inhibitor treatment effectively increased the citric acid content in citrus callus, and the transcript levels of several citric acid metabolism genes were inhibited, which means that CitHAT may regulate citric acid metabolism through these genes. Our study associates the potential function of histone acetyltransferases in citrate metabolism and extends the molecular mechanism of citrate metabolism in fruits.