Systematic identification and expression profiles of the BAHD superfamily acyltransferases in barley (Hordeum vulgare)

BAHD superfamily acyltransferases play an important role in catalyzing and regulating secondary metabolism in plants. Despite this, there is relatively little information regarding the BAHD superfamily in barley. In this study, we identified 116 HvBAHD acyltransferases from the barley genome. Based on phylogenetic analysis and classification in model monocotyledonous and dicotyledonous plants, we divided the genes into eight groups, I-a, I-b, II, III-a, III-b, IV, V-a and V-b. The Clade IV genes, including Agmatine Coumarol Transferase (ACT) that is associated with resistance of plants to Gibberella fungi, were absent in Arabidopsis. Cis-regulatory element analysis of the HvBAHDs showed that the genes respond positively to GA3 treatment. In-silico expression and qPCR analysis showed the HvBAHD genes are expressed in a range of tissues and developmental stages, and highly enriched in the seedling stage, consistent with diverse roles. Single nucleotide polymorphism (SNP) scanning analysis revealed that the natural variation in the coding regions of the HvBAHDs is low and the sequences have been conserved during barley domestication. Our results reveal the complexity of the HvBAHDs and will help facilitate their analysis in further studies.