[Genome-wide identification of Atropa belladonna WRKY transcription factor gene family and analysis of expression...

Based on whole genome data, the identification and expression pattern analysis of the Atropa belladonna WRKY transcription factor family were conducted to provide a theoretical foundation for studying the biological functions and mechanisms of these transcription factors. In this study, bioinformatics methods were employed to identify members of the A. belladonna WRKY gene family and to predict their physicochemical properties, conserved motifs, promoter cis-acting elements, and chromosomal localization. Additionally, the expression patterns of the A. belladonna WRKY gene family under the regulation of environmental factors such as light quality and temperature were analyzed. The results revealed a total of 28 AbWRKY transcription factors, randomly distributed across 16 chromosomes, encoding 324-707 amino acids. Most AbWRKY proteins were acidic, unstable, and hydrophilic. Based on multiple sequence alignment and phylogenetic analysis, the WRKY gene family members were classified into two subfamilies. Conserved motif and domain analysis indicated that WRKY transcription factors in the same subfamily possessed conserved structural features. Promoter analysis predicted that the A. belladonna WRKY family contained light-responsive elements, hormone-responsive elements, and stress-responsive elements. Collinearity analysis showed that AbWRKY24 plays a crucial role in the expansion of the AbWRKY gene family. Then qRT-PCR results indicated that AbWRKY6, AbWRKY8, AbWRKY14, and AbWRKY24 responded to red light stress, while AbWRKY8, AbWRKY14, and AbWRKY24 responded to yellow light/low-temperature combined stress. AbWRKY6 and AbWRKY8 were significantly expressed in leaves and stems, AbWRKY27 and AbWRKY28 were significantly expressed in fibrous roots, and AbWRKY25 was significantly expressed in flowers. This study is the first to identify and analyze the WRKY gene family in A. belladonna and to examine its expression patterns under light and temperature regulation, laying a foundation for in-depth analysis and functional validation of the molecular mechanisms of A. belladonna WRKY transcription factors in responding to light quality and temperature environmental factors.