Genome-Wide Analysis of HECT E3 Ligases Members in Phyllostachys edulis Provides Insights into the Role of PeHECT1 in Plant Abiotic Stress Response

Homology to E6-AP Carboxy Terminus (HECT) E3 ubiquitin ligases play pivotal roles in plant growth, development, and responses to abiotic stresses. However, the function of HECT genes in <i>Phyllostachys edulis</i> (<i>P. edulis</i>) remains largely uninvestigated. In this study, a comprehensive genome-wide analysis of the HECT E3 ubiquitin ligases gene family in <i>P. edulis</i> was conducted, aiming to elucidate its evolutionary relationships and gene expansion. Analysis of gene structure, conserved motifs and domains, and synteny genome regions were performed. Furthermore, cis-elements in HECT gene promoters that respond to plant hormones and environmental stresses were identified and corroborated by expression data from diverse abiotic stress conditions and hormone treatments. Based on the co-expression network of PeHECTs under cold and dehydration stresses, <i>PeHECT1</i> was identified as a key candidate gene associated with abiotic stress tolerance. Overexpression of <i>PeHECT1</i> in tobacco leaves significantly upregulated genes related to reactive oxygen species (ROS) detoxification and polyamine biosynthesis. Yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), and dual-luciferase (dual-LUC) assays suggested that the transcription factor ETHYLENE RESPONSE FACTOR 3 (PeERF3) bound to the dehydration-responsive element (DRE) of the promoter of <i>PeHECT1</i> and activated its transcription activity. Phylogenetic analysis indicated that PeHECT1 in <i>P. edulis</i> exhibited a close association with the diploid herbaceous bamboo <i>Olyra latifolia</i>, followed by the divergence of rice and bamboo. In summary, this study enhances our comprehensive understanding of the HECT E3 ubiquitin ligases gene family in <i>P. edulis</i> and highlights the potential role of <i>PeHECT1</i> in plant abiotic stress response.