DataSheet1_Genome-wide identification and bioinformatics analysis of the WRKY transcription factors and screening of candidate genes for anthocyanin biosynthesis in azalea (Rhododendron simsii).docx

WRKY transcription factors have been demonstrated to influence the anthocyanin biosynthesis in many plant species. However, there is limited knowledge about the structure and function of WRKY genes in the major ornamental plant azalea (Rhododendron simsii). In this study, we identified 57 RsWRKY genes in the R. simsii genome and classified them into three main groups and several subgroups based on their structural and phylogenetic characteristics. Comparative genomic analysis suggested WRKY gene family has significantly expanded during plant evolution from lower to higher species. Gene duplication analysis indicated that the expansion of the RsWRKY gene family was primarily due to whole-genome duplication (WGD). Additionally, selective pressure analysis (Ka/Ks) suggested that all RsWRKY duplication gene pairs underwent purifying selection. Synteny analysis indicated that 63 and 24 pairs of RsWRKY genes were orthologous to Arabidopsis thaliana and Oryza sativa, respectively. Furthermore, RNA-seq data was used to investigate the expression patterns of RsWRKYs, revealing that 17 and 9 candidate genes may be associated with anthocyanin synthesis at the bud and full bloom stages, respectively. These findings provide valuable insights into the molecular mechanisms underlying anthocyanin biosynthesis in Rhododendron species and lay the foundation for future functional studies of WRKY genes.

WRKY转录因子已被证实对多种植物物种的类黄酮生物合成产生影响。然而，关于主要观赏植物杜鹃（Rhododendron simsii）中WRKY基因的结构与功能，尚缺乏深入了解。在本研究中，我们从R. simsii基因组中鉴定出57个RsWRKY基因，并根据其结构和系统发育特征将其分为三大类及若干亚类。比较基因组分析表明，WRKY基因家族在植物从低等物种向高等物种进化的过程中经历了显著的扩张。基因复制分析指出，RsWRKY基因家族的扩张主要归因于全基因组复制（WGD）。此外，选择性压力分析（Ka/Ks）表明，所有RsWRKY复制基因对均经历了净化选择。同源分析显示，63和24对RsWRKY基因分别与拟南芥（Arabidopsis thaliana）和水稻（Oryza sativa）的基因同源。进一步地，通过RNA测序数据研究了RsWRKY的表达模式，揭示出17和9个候选基因可能与花蕾期和完全开放期中的类黄酮合成相关。这些发现为揭示杜鹃属中类黄酮生物合成的分子机制提供了宝贵见解，并为WRKY基因的功能研究奠定了基础。