Identification and expression analysis of the AHL gene family in grape (Vitix vinifera)

Abstract AT-Hook Motif Nuclear Localized (AHL) proteins is a small DNA binding protein motif. It was first found in the high-mobility-group (HMG-I/Y) of mammalian non-histone chromosomal protein, which is different from other known DNA binding protein motifs. In order to reveal the basic characteristics of AHL gene family in grape, this study used biological information technology to identify the members of grape AHL genes, and analyzed its physical and chemical properties, cis-acting element, codon usage bias, gene structure, conservative motif and phylogenetic relationship. The study identified 14 members in the AHL gene family of grape. Phylogenetic analysis showed that AHL proteins from grape can be classified into two branches, class I and class II. And nearly all VvAHLs members in the same branch displayed similar motif distributions and gene structures, which might be related to their same executive functions. Subcellular localization showed that most of the VvAHL genes are located in Extracellular matrix, mitochondrion, nucleus, cytoplasm and other organelles related to photosynthesis and respiration. All of the 14 VvAHLs possess a number of light response-, stress response-, and hormone response-related cis-elements in the promoter sequences. The real-time fluorescence quantification technique was used to analyze the response of grape AHL genes under various hormone induction and adversity stress. The results showed that the expression of VvAHL gene was significantly regulated under the hormone induction and the adversity stress. It is suggested that VvAHLs play an important role in growth and development of grape, organ formation and defense response to adversity. This study will provide the basis for further analysis of AHL genes function, and lay the foundation for in-depth study of AHL genes in grape.