Abstract
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.