Genome-Wide Identification and Expression Analysis of the HD-Zip Gene Family in Moso Bamboo (Phyllostachys edulis)

Homeodomain-leucine zipper (HD-Zip) transcription factors are unique to plants and play important roles in plant growth and development. Although the HD-Zip gene family has been studied in many plant species, no comprehensive analysis of gene expression patterns under stress conditions has been reported in moso bamboo (Phyllostachys edulis). In this study, 48 putative HD-Zip genes were identified in the moso bamboo genome, and the predicted proteins clustered into four subfamilies (HD-Zip I-IV) based on phylogenetic analysis. Members of each subfamily shared similar conserved motifs, implying that they may perform similar functions. Our evolutionary analyses revealed that HD-Zip genes underwent a large-scale duplication event approximately 15 million years ago, the duplicated HD-Zip genes in moso bamboo are basically under purifying selection, and that the divergence time of HD-Zip genes between rice and moso bamboo was 15-23 million years ago. Analyses of expression in response to drought and salinity showed that some genes display stress-inducible expression patterns. Our study provides a systematic analysis of the HD-Zip gene family in moso bamboo. Analysis of gene expression patterns under abiotic stress may help in understanding the role of HD-Zip genes in moso bamboo and in overcoming challenges in moso bamboo growth and development.