Genome-wide identification and salt stress expression analysis of the PLATZ transcription factor genes in Betula platyphylla.

The PLATZ (Plant AT rich protein and zinc binding protein) transcription factor, which is a type of plant specific zinc dependent DNA binding protein, participates in regulating the process of plant growth and environmental stress responses. In order to clarify the characteristics of the PLATZ family genes in birch (Betula platyphylla), the members of the PLATZ family were screened and analyzed in this study. Totals of ten BpPLATZ genes were identified in birch genome and classified into five groups base on phylogenetic relationship, BpPLATZ genes in the same group usually possess a similar motif composition, exon or intron number. These ten genes distributed on eight chromosomes of fourteen chromosomes of birch. In addition, various cis-elements were distributed in the promoter regions of BpPLATZs, especially with abundant MYC, ABRE and MYB, which were reported to be involved in salt stress responses. The RT-qPCR analysis results show that most genes have the higher expression levels in the roots compared to leaves and stems in birch. BpPLATZ3, BpPLATZ5, BpPLATZ6, BpPLATZ7 and BpPLATZ8 are significantly induced expressed response to salt stress. These studies provide a basis for the further functional study of the BpPLATZ genes.