Genome-Wide Characterization of the PLATZ Gene Family in Medicago truncatula and Their Expression Profiles in Response to Abiotic Stress

Abstract

Simple Summary PLATZ transcription factors are a plant-specific family of zinc finger proteins that play important roles in regulating plant growth, development, and abiotic stress responses. In the legume model plant Medicago truncatula, the PLATZ gene family has not been systematically characterized. In this study, a total of 16 MtPLATZ genes were identified in the M. truncatula genome and classified into four distinct subgroups based on phylogenetic analysis. This family includes five segmental duplication pairs and one tandem duplication pair, all of which have Ka/Ks ratios less than 1, indicating that MtPLATZ genes have experienced strong purifying selection during evolution. Cis-acting element analysis revealed that the promoter regions of MtPLATZ genes contain multiple stress-responsive and hormone-responsive elements, suggesting their potential extensive involvement in environmental adaptation. Preliminary expression profiling under various abiotic stresses, including PEG-induced osmotic stress, acute NaCl shock, acute heat shock, and acute cold shock, demonstrated that MtPLATZ genes exhibit treatment-specific and time-dependent expression patterns, indicating that they may have functional divergence. This study provides a systematic analysis of the MtPLATZ gene family in M. truncatula, offering a valuable reference for functional studies and genetic improvement of stress tolerance in legumes.