AUTHOR=Zhang Wei-Meng , Fang Da , Cheng Xiu-Zhu , Cao Jun , Tan Xiao-Li 

TITLE=Insights Into the Molecular Evolution of AT-Hook Motif Nuclear Localization Genes in Brassica napus

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.714305

DOI=10.3389/fpls.2021.714305

ISSN=1664-462X

ABSTRACT=<p>AT-hook motif nuclear localization (AHL) proteins belong to a family of transcription factors, and play important roles in plant growth and development and response to various stresses through protein-DNA and protein-protein interactions. To better understand the <italic>Brassica napus AHL</italic> gene family, <italic>AHL</italic> genes in <italic>B. napus</italic> and related species were analyzed. Using <italic>Arabidopsis</italic> as a reference, 122 <italic>AHL</italic> gene family members were first identified in <italic>B. napus</italic>. According to the phylogenetic tree and gene organization, the BnaAHLs were classified into two clades (Clade-A and Clade-B) and three types (Type-I, Type-II, and Type-III). Gene organization and motif distribution analysis suggested that the <italic>AHL</italic> gene family is relatively conserved during evolution. These <italic>BnaAHLs</italic> are unevenly distributed on 38 chromosomes and expanded by whole-genome duplication (WGD) or segmental duplication. And large-scale loss events have also occurred in evolution. All types of <italic>BnaAHLs</italic> are subject to purification or neutral selection, while some positive selection sites are also identified in Type-II and Type-III groups. At the same time, the purification effect of Type-I members are stronger than that of the others. In addition, RNA-seq data and <italic>cis</italic>-acting element analysis also suggested that the BnaAHLs play important roles in <italic>B. napus</italic> growth and development, as well as in response to some abiotic and biotic stresses. Protein-protein interaction analysis identified some important BnaAHL-binding proteins, which also play key roles in plant growth and development. This study is helpful to fully understand the origin and evolution of the <italic>AHL</italic> gene in <italic>B. napus</italic>, and lays the foundation for their functional studies.</p>