目的 对白蜡树Fraxinus chinensis WRKY基因家族进行鉴定、生物信息学和密码子偏好性分析。方法 基于白蜡树全长转录组数据，利用生物信息学方法对其WRKY基因家族进行鉴定，并对其理化性质、系统发育、保守基序进行分析；基于白蜡树叶片和枝皮的二代转录组数据，对白蜡树WRKY基因家族的表达模式进行分析，并采用实时荧光定量PCR方法进行验证；利用CodonW、EMBOSS等程序对密码子偏好性进行分析，并进行最优密码子分析、中性绘图、ENC-plot和PR2偏倚分析。结果 共鉴定得到49个WRKY转录因子，均为酸性、亲水蛋白，编码氨基酸数目为426～2 175，相对分子质量33 933.48～179 137.94，理论等电点4.91～5.27，不稳定蛋白占比65.31%，预测均定位到细胞核；系统进化表明FcWRKY基因家族成员归为Ⅰ（11个）、Ⅱ（30个）、Ⅲ（7个）大类以及2个特殊成员（FcWRKY23和FcWRKY37），其中第Ⅱ类分为Ⅱa（5个）、Ⅱb（5个）、Ⅱc（8个）、Ⅱd（7个）、Ⅱe（7个）5个亚类；Motif 1和Motif 2存在于所有的WRKY转录因子中，是其保守序列；二代转录组数据筛选到16个WRKY基因在叶片和枝皮中具有显著差异表达，其中仅有FcWRKY11在枝皮中的表达量高于叶片。白蜡树FcWRKYs偏好使用以A/U结尾的密码子，并且偏好性较弱；确定了3个最优密码子，分别是CUU、AGG、和UAU；中性绘图分析和ENC-plot分析均表明自然选择是影响其密码子偏好性的主要因素，PR2偏倚分析结果表明突变压力亦影响其密码子偏好性。结论 鉴定了白蜡树WRKY基因，其中8个WRKY基因表达量与转录组学测序结果趋势一致，为研究白蜡树WRKY的基因功能奠定基础。

Objective The aim of this study was to perform identification and bioinformatics and codon preference analysis of WRKY gene family of Fraxinus chinensis. Methods Based on the full-length transcriptome data of F. chinensis, the WRKY gene family was identified using bioinformatics methods and their physicochemical properties, phylogeny, conservative motifs were analyzed. Based on the second generation transcriptome data, expression patterns of WRKY gene family were analyzed and verified by real time fluorescence quantitative PCR. The codon bias was analyzed by CodonW and EMBOSS program, the optimal codon analysis, neutral plotting, ENC plot and PR2 bias analysis were also performed. Results A total of 49 WRKY genes were identified, all of them were acidic and hydrophilic proteins with an amino acid sequence varying from 426 to 2 175, molecular weight between 33 933.48 and 179 137.94, an isoelectric point between 4.91 and 5.27, unstable proteins accounted for 65.31%, and all of them were located in the nucleus. The phylogenetic tree showed that FcWRKY genes were assigned to Ⅰ (11),Ⅱ (30), Ⅲ (7) three categories and two special members (FcWRKY23 and FcWRKY37), the second category was divided into five subclass, including Ⅱa (5), Ⅱb (5), Ⅱc (8), Ⅱd (7) and Ⅱe (7); Conserved motif analysis showed that Motif 1 and Motif 2 were found in all WRKY transcriptional factors. A total of 16 significant differential expression WRKY genes in leaves and bark were identified, of which only FcWRKY11 was high expressed in bark than in leaves. The results of codon bias analysis showed that the FcWRKYs prefered to use codons ending in A/U weak codon usage. The optimal codons were identified, which were CUU, AGG and UAU; The results of neutrality plot analysis and ENC plot analysis indicated that natural selection was the main factor affecting its codon bias, PR2 bias analysis indicated that mutation pressure also had impact on codon preference. Conclusion It laid a theoretical foundation for the study of WRKY gene function in F. chinensis.

R286.12

陕西中医药大学秦药特色资源研究开发重点实验室开放课题（KF202326）；陕西省教育厅青年创新团队建设科研计划项目（21JP031）；陕西高校青年创新团队资助项目（陕教［2019］90号）；陕西中医药大学校级科研课题（2023GP32）；云南省科技厅基础研究专项资助项目（202101AU070005）