Genome-Wide Identification and Expression Analysis of the <i>PIN</i> Auxin Transporter Gene Family in <i>Zanthoxylum armatum</i> DC

Abstract

PIN-formed (PIN) proteins are important auxin carriers that participate in the polar distribution of auxin in plants. In this study, 16 ZaPIN genes were identified from the whole genome of Zanthoxylum armatum DC. The physicochemical properties and structure of PIN proteins were determined, and the gene sequences and promoter regions were analyzed to identify cis-acting elements and conserved motifs. The transcript profiles of ZaPIN genes in different tissues and in response to auxin and gibberellin treatments were also analyzed. A phylogenetic analysis separated the 16 ZaPIN genes into four groups. The ZaPIN genes showed the closest evolutionary relationship to those of Citrus sinensis and the most distant evolutionary relationship to those of Oryza sativa. A cis-element analysis revealed a large number of cis elements in ZaPIN promoter regions related to plant hormones, plant growth and development, and stress stimuli, suggesting that ZaPINs have a wide range of biological activities. Additionally, gene expression profiling revealed that ZaPINs had different expression patterns in nine tissues. Further qRT-PCR analyses revealed that most ZaPINs were upregulated by auxin and gibberellin in young leaves. Our results provide useful information for further structural and functional analyses of the ZaPIN gene family in Z. armatum.

Keywords

• <i>Zanthoxylum armatum</i> DC
• <i>PIN</i> gene family
• bioinformatic analysis
• auxin