Genome-Wide Identification of WRKY Gene Family in Angraecum sesquipedale and their Response to abiotic Stress

WRKY transcription factors are key regulators of plant stress responses, growth and development, and secondary metabolism. Angraecum sesquipedale has high ornamental value, but its growth is restricted by environmental stresses, and the functional roles of its WRKY genes under abiotic stress remain unclear. In this study, a total of 62 WRKY genes ( AsWRKYs ) were identified from the genome of A. sesquipedale . Their chromosome distribution, evolutionary driving force, phylogeny, gene structure and promoter cis-elements were analyzed, along with tissue-specific expression profiling. RNA-seq and qRT-PCR were used to detect their expression changes under cold stress. The results showed that AsWRKYs were unevenly distributed on 16 chromosomes and unchr155, segmental duplication was the main driving force for the expansion of the AsWRKY family, and they could be divided into three evolutionary groups. The promoters contained a large number of hormone- and abiotic stress-responsive cis-elements. 17 AsWRKYs were upregulated to varying degrees under prolonged cold stress, among which 10 were upregulated more than 10-fold. This study provides a genomic basis for further functional verification of AsWRKY genes and supports the development of cold-resistant breeding strategies for A. sesquipedale .