School of Pharmacy and Life Science, Jiujiang University, Jiujiang, China.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China.
BMC Plant Biol. 2022 Mar 14;22(1):115. doi: 10.1186/s12870-022-03511-1.
Akebia trifoliata, belonging to the Lardizabalaceae family, is a well-known Chinese traditional medicinal plant, susceptible to many diseases, such as anthracnose and powdery mildew. WRKY is one of the largest plant-specific transcription factor families and plays important roles in plant growth, development and stress response, especially in disease resistance. However, little was known about the numbers, characters, evolutionary relationship and expression of WRKY genes in A. trifoliata in response to plant disease due to lacking of A. trifoliata genome.
A total of 42 putative AktWRKY genes were identified based on the full-length transcriptome-sequencing data of A. trifoliata. Then 42 AktWRKY genes were divided into three major groups (Group I-III) based on the WRKY domains. Motif analysis showed members within same group shared a similar motif composition, implying a functional conservation. Tissue-specific expression analysis showed that AktWRKY genes could be detected in all tissues, while few AktWRKY genes were tissue specific. We further evaluated the expression of AktWRKY genes in three varieties in response to Colletotrichum acutatum by qRT-PCR. The expression patterns of AktWRKY genes were similar between C01 and susceptible variety I02, but distinctly different in resistant variety H05. In addition, it showed that more than 64 percentages of AktWRKY genes were differentially expressed during fungal infection in I02 and H05. Furthermore, Gene ontology (GO) analysis showed that AktWRKY genes were categorized into 26 functional groups under cellular components, molecular functions and biological processes, and a predicted protein interaction network was also constructed.
Results of bioinformation analysis and expression patterns implied that AktWRKYs might play multiple function in response to biotic stresses. Our study could facilitate to further investigate the function and regulatory mechanism of the WRKY in A. trifoliata during pathogen response.
三叶木通（Akebia trifoliata）隶属木通科木通属，是一种著名的传统中药植物，易受炭疽病和白粉病等多种病害的影响。WRKY 是最大的植物特异性转录因子家族之一，在植物生长、发育和应激反应中发挥重要作用，特别是在抗病性方面。然而，由于缺乏三叶木通的基因组，对三叶木通中 WRKY 基因的数量、特征、进化关系和表达以及对植物病害的反应知之甚少。
基于三叶木通全长转录组测序数据，共鉴定出 42 个推定的 AktWRKY 基因。然后，根据 WRKY 结构域将 42 个 AktWRKY 基因分为三大类（I-III 组）。基序分析表明，同一组内的成员共享相似的基序组成，暗示其功能保守。组织特异性表达分析表明，AktWRKY 基因可在所有组织中检测到，但少数 AktWRKY 基因具有组织特异性。我们进一步通过 qRT-PCR 评估了 3 个品种在响应炭疽菌时 AktWRKY 基因的表达。C01 和感病品种 I02 的 AktWRKY 基因表达模式相似，但在抗性品种 H05 中则明显不同。此外，结果表明，在 I02 和 H05 中，真菌感染时超过 64%的 AktWRKY 基因表达差异。此外，GO 分析表明，AktWRKY 基因在细胞成分、分子功能和生物过程中被归类为 26 个功能组，并且还构建了一个预测的蛋白质相互作用网络。
生物信息学分析和表达模式的结果表明，AktWRKYs 可能在应对生物胁迫方面发挥多种功能。我们的研究可以促进进一步研究 WRKY 在三叶木通对病原体响应过程中的功能和调控机制。
