PfTALE5 Acts as a hub for multi-stress resilience: a genome-wide study of the TALE family in Paulownia fortunei

Abstract

Background: The Three-Amino-Acid-Loop-Extension (TALE) transcription factors are key regulators of plant development and stress responses. However, a systematic study of the TALE gene family in Paulownia fortunei has not been reported to date. Results: Here, we conducted the first genome-wide analysis and identified 38 PfTALE genes, which were phylogenetically classified into the KNOXI, KNOXII, and BELL subfamilies. These genes were unevenly distributed across 15 chromosomes. Promoter analysis revealed abundant cis-elements associated with light, hormones, and stress. Transcriptome profiling and qRT-PCR analyses showed that PfTALEs were differentially induced by drought, salt, and phytoplasma infection. Among them, PfTALE5, PfTALE12, PfTALE16, and PfTALE18 were significantly responsive to all three stresses, suggesting pivotal roles in stress adaptation. Notably, PfTALE5 exhibited consistent and strong upregulation under all stress conditions and was localized to both the nucleus and cytomembrane. Furthermore, yeast two-hybrid assays and molecular docking confirmed that PfTALE5 physically interacts with PfKNAT7 via hydrogen bonds, implying their cooperative function in stress response regulation. Conclusions: Our study provides the first comprehensive genomic and functional insights into the TALE gene family in P. fortunei, highlighting PfTALE5 as a key regulator conferring multi-stress resilience. These findings offer valuable genetic targets and strategic guidance for breeding stress-resistant woody cultivars.