Genome-Wide Comparative Analysis of WRKY Gene Family Explores Insight Into the Evolution and Expression Divergence in...

Wheat (Triticum aestivum L.), a globally significant cereal crop, plays a crucial role in human nutrition and agricultural systems. Recent studies have extensively examined the role of transcription factors across various plant genomes. However, comprehensive comparative genomic analyses of the WRKY gene family across various diploid, tetraploid, and hexaploid wheat genomes remain limited. Here, we conducted a detailed analysis of the WRKY gene family in one diploid, two tetraploid, and five hexaploid wheat genomes, identifying a total of 1912 WRKY genes. Consistent with previous reports, the genes were classified into three groups according to their conserved domain and motif architectures. Phylogenetic reconstruction resolved clear clades, with Group II forming the largest and most diverse branch. Tandem duplication events were found to significantly impact the expansion of the WRKY gene family, particularly in the T. aestivum acc. Chinese Spring genome, which exhibited the highest number of tandemly duplicated genes. Analysis of A subgenomes in polyploid wheat genomes suggested potential gene loss following polyploid formation. Expression profiling of WRKY genes in bread wheat under salt stress and autophagy inhibition conditions uncovered differential expression patterns and significant divergence among tandemly duplicated genes. This study provides valuable insights into the distribution, phylogenetic relationships, and expression patterns of WRKY genes in wheat. Our findings highlight the role of tandem duplication in driving functional divergence, offering important genetic resources for wheat gene editing and genome-assisted breeding.