TY - EJOU AU - Li, Huifeng AU - Zhao, Qiang AU - Wang, Hai AU - Dong, Qinglong AU - Xu, Yi TI - Genome-Wide Identification, Expression Profiling and Protein-Protein Interaction Properties of the BEL-Like Homeodomain Gene Family in Apple T2 - Phyton-International Journal of Experimental Botany PY - 2022 VL - 91 IS - 2 SN - 1851-5657 AB - BEL1-like homeodomain (BLH) family proteins are homeodomain transcription factors, which are found ubiquitously in plants and play important roles in regulating meristem and flower development. Although BLH proteins have been reported in some plant species, there is very little information available for plants in the Malus genus (e.g., apple tree:Malus domestica). In the present study, we identified 19 apple MdBLH genes. Phylogenetic analysis revealed that the MdBLH genes could be divided into five groups. Analysis of gene structure showed that MdBLH gene has four exons, and the third exon was 61 bp in length. Chromosomal location analysis suggested that the MdBLH genes are not distributed uniformly on 12 chromosomes. Eleven MdBLH genes were cloned by RT-PCR, and their expression patterns were also determined. Among them, the expression levels of MdBLH4.1 and MdBLH9.1 could be induced by sodium chloride stress, while the expression levels of MdATH1.1, MdBLH8.1, MdBLH8.3, and MdBLH11.1 were down-regulated by such stress. Transcriptional levels of MdATH1.1 and MdBLH7.2 were down-regulated by mannitol stress. The result of yeast two-hybrid experiment showed that MdBEL1.1 interacted with apple ovate family proteins 6 (MdOFP6), and MdBLH3.1 interacted with the MdOFP4, MdOFP6, MdOFP13, and MdOFP16 proteins. Our results provide a strong theoretical basis and a valuable reference for analyzing of the biological functions of MdBLH proteins as transcription factors in apple growth, development, and stress and also for the construction of regulatory networks. KW - Apple; BEL-like homeodomain; gene cloning; expression analysis; interaction analysis DO - 10.32604/phyton.2022.016951