Affiliation:
1. College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China
2. Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization, College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Abstract
As an important genus in Orchidaceae, Cymbidium has rich ecological diversity and significant economic value. DNA binding with one zinc finger (Dof) proteins are pivotal plant-specific transcription factors that play crucial roles in the growth, development, and stress response of plants. Although the Dof genes have been identified and functionally analyzed in numerous plants, exploration in Orchidaceae remains limited. We conducted a thorough analysis of the Dof gene family in Cymbidium goeringii, C. ensifolium, and C. sinensis. In total, 91 Dof genes (27 CgDofs, 34 CeDofs, 30 CsDofs) were identified, and Dof genes were divided into five groups (I–V) based on phylogenetic analysis. All Dof proteins have motif 1 and motif 2 conserved domains and over half of the genes contained introns. Chromosomal localization and collinearity analysis of Dof genes revealed their evolutionary relationships and potential gene duplication events. Analysis of cis-elements in CgDofs, CeDofs, and CsDofs promoters showed that light-responsive cis-elements were the most common, followed by hormone-responsive elements, plant growth-related elements, and abiotic stress response elements. Dof proteins in three Cymbidium species primarily exhibit a random coil structure, while homology modeling exhibited significant similarity. In addition, RT-qPCR analysis showed that the expression levels of nine CgDofs changed greatly under heat stress. CgDof03, CgDof22, CgDof27, CgDof08, and CgDof23 showed varying degrees of upregulation. Most upregulated genes under heat stress belong to group I, indicating that the Dof genes in group I have great potential for high-temperature resistance. In conclusion, our study systematically demonstrated the molecular characteristics of Dof genes in different Cymbidium species, preliminarily revealed the patterns of heat stress, and provided a reference for further exploration of stress breeding in orchids.
Funder
Technical Services for Introduction and Domestication of Orchids in Sanjiangkou Botanical Garden, Fuzhou