Identification of stress-related characteristics of the <i>WRKY</i> gene family: A case study of <i>Dendrobium catenatum</i>

Abstract

As one of the largest families of transcription factors (TFs) in plants, the WRKY TF family plays a key role in regulating plant responses to various biotic and abiotic stresses. However, there is no confirmed method to quickly identify stress-responsive members from the <italic>WRKY</italic> gene family. In this study, all reported functional <italic>WRKY</italic> genes were first analyzed, and the amino acid patterns in response to stress were identified in group II-c (T-R/K-S/T-E/Q/D-V/I/L-E/D-I/V/H/N-L/M-D/E-D-G/E-F/Y-K/R-WRKYG-Q/K-K-A/T-VKN-S/N-P), group II-d (VPA-I/V-S-X-K-M/L/V/I-ADIP-P/A/V-D-D/E-Y/F-S-WRKYGQKPIKGSP-H/Y-PRGYYKCS-S/T-V/M-RGCPARKVER), and group II-e (PSD-S/A/L-WAWRKYGQKPIKGSPYPR-G/S-YYRCSSSKGC). <italic>WRKY</italic> genes in<italic> Dendrobium catenatum</italic> were used to validate the accuracy of these patterns. A total of 63 <italic>DcaWRKY</italic> genes were identified, their gene structures, conserved motifs, and gene expression patterns were analyzed, and a phylogenetic tree was constructed. Gene expression patterns were then analyzed under drought stress, and seven <italic>DcaWRKY</italic> genes (<italic>Dca002550</italic>, <italic>Dca002715</italic>, <italic>Dca005648</italic>, <italic>Dca007842</italic>, <italic>Dca010430</italic>, <italic>Dca016437</italic>, and <italic>Dca006787</italic>) were randomly selected to determine their expression levels and verify their expression patterns by quantitative real-time polymerase chain reaction analysis. The identified amino acid patterns were validated by drought-responsive <italic>WRKY</italic> genes in <italic>D. catenatum</italic>, confirming the accuracy of these amino acid patterns and providing valuable insights into further research of the <italic>WRKY</italic> family in <italic>D. catenatum</italic>.