Genome-wide characterisation and expression analysis of PLATZ gene family of Eucalyptus grandis under arbuscular mycorrhizal symbiosis

Introduction Arbuscular mycorrhizal fungi (AMF) affect plant performance and ecosystem functioning. The Plant AT-rich protein and zinc-binding protein ( PLATZ ) transcription factor family plays a pivotal role in the plant growth and meristem activity. However, the potential role of PLATZ genes in regulating arbuscular mycorrhizal (AM) symbiosis remains experimentally uncharacterized. Methods This study aimed to identify the PLATZ genes in Eucalyptus grandis and to preliminarily characterize their dual involvement in both growth regulation and AM symbiosis. A genome-wide identification and expression analysis of EgPLATZ genes was conducted through bioinformatics approaches and transcriptomic data. Results Twenty EgPLATZ members were identified and classified into 4 distinct clades, which is consistent with conserved domain architectures observed in other plant species. EgPLATZs are enriched in cis-regulatory motifs associated with cell expansion, phytohormone signaling, meristem activity, and mycorrhizal symbiosis, especially NODCON2GM (100%), PIBS (50%) and AW-box (75%). The protein predictions suggest that EgPLATZ proteins interact with Dof proteins and transcription initiation factors, indicating a conserved transcriptional mechanism analogous to that observed in other species. EgPLATZs exhibit tissue-specific expression patterns, and EgPLATZ14 and EgPLATZ15 were highly expressed in roots and leaves, respectively. Six EgPLATZs were generally down-regulated under AM symbiosis, with EgPLATZ15 and EgPLATZ2 showing significant downregulation. Discussion These results suggest that certain EgPLATZs may function at the interface of developmental signaling and mycorrhizal colonization. This study provides the genome-wide characterization of PLATZs in E. grandis , establishing a functional framework for future investigations into their roles in growth and symbiosis, and suggestion potential candidate genes involved in AMF-responsive in E. grandis .