Genome-Wide Identification and Salt Stress-Responsive Expression Analysis of the GmPLATZ Gene Family in Soybean (Glycine max L.)

The plant-specific <i>PLATZ</i> transcription factors play crucial roles in plant growth, development, and responses to abiotic stresses. However, despite their functional significance, <i>PLATZ</i> genes remain poorly characterized in soybeans. In this study, we conducted a genome-wide analysis of the <i>GmPLATZ</i> gene family and investigated their expression profiles under salt stress. We identified a total of 29 <i>GmPLATZ</i> genes in the soybean genome and systematically analyzed their physicochemical properties, conserved domains, evolutionary relationships, cis-acting elements, and expression regulation patterns. Subcellular localization predictions indicated nuclear localization for most <i>GmPLATZs</i>, except for <i>GmPLATZ5</i> and <i>GmPLATZ14</i>, which showed dual chloroplast-nuclear localization. A gene family expansion analysis indicated that 21 segmental duplication events were the primary driver of <i>GmPLATZ</i> diversification. A phylogenetic analysis classified the <i>GmPLATZ</i> genes into four subgroups, while gene structure and motif analyses revealed conserved zinc-binding domains and identified multiple cis-acting elements associated with light responsiveness, hormone signaling, and stress responses. Expression profiling showed tissue-specific expression patterns, with 13 <i>GmPLATZ</i> genes differentially expressed under salt stress, including root-preferential members (e.g., <i>GmPLATZ1</i>, <i>GmPLATZ10</i>) and leaf-preferential members (e.g., <i>GmPLATZ8</i>, <i>GmPLATZ9</i>). This study provides a theoretical basis for further investigation of <i>GmPLATZ</i> gene functions in soybean development and stress tolerance.