# Genome-Wide Identification and Analysis of bZIP Transcription Factor Gene Family in Broomcorn Millet (Panicum miliaceum L.)

## TL;DR

This study identifies and analyzes 144 bZIP transcription factor genes in broomcorn millet, revealing their roles in stress response and seed germination.

## Contribution

The first genome-wide analysis of the bZIP gene family in broomcorn millet, including expression patterns under salt stress.

## Key findings

- 144 bZIP transcription factors were identified and grouped into eleven subfamilies.
- 18 PmbZIP genes showed differential expression during seed germination under salt stress.
- Promoter analysis revealed hormone and stress responsiveness in PmbZIP genes.

## Abstract

Background: Basic (region) leucine zippers (bZIPs) make up one of the largest families and are some of the most prevalent evolutionarily conserved transcription factors (TFs) in eukaryotic organisms. Plant bZIP family members are involved in seed germination, vegetative growth, flower development, light response, and various biotic/abiotic stress response pathways. Nevertheless, a detailed identification and genome-wide analysis of the bZIP family genes in broomcorn millet have not been conducted. Methods: In this research, we performed genome-wide identification, phylogenetic analysis, cis-elements analysis, and expression pattern analysis. Results: 144 bZIP transcription factors were identified from the P. miliaceum genome and classified into eleven subfamilies using a phylogenetic analysis. Motif and bZIP domain sequence alignment analyses indicated that the members in each subfamily were relatively conserved. Furthermore, a promoter analysis revealed that bZIP transcription factor family genes were responsive to multiple hormones and environmental stresses. Additionally, cis-element MYB binding sites were identified in the promoters of most PmbZIP genes. A gene expression analysis showed that 18 PmbZIP genes were differentially expressed during seed germination in salt stress, with 7 being significantly downregulated and 11 upregulated, thus suggesting that these PmbZIP genes may play an important role in the salt stress response and seed germination. Conclusions: Current research provides valuable information for further functional analyses of the PmbZIP gene family and as a reference for future studies on broomcorn millet’s stress response.