新疆野苹果WRKY基因家族鉴定及低温沙藏过程中的表达模式分析OA

[Objective]This study aimed to conduct a genome-wide identification of the WRKY tran-scription factor(TF)family in Malus sieversii(Ledeb.)Roem.and screen for differentially expressed transcription factors in its seeds during low-temperature sand storage stratification,to provide a theoretical basis for the study of WRKY gene functions in M.sieversii.[Method]The candidate members of the WRKY family in M.sieversii were initially identified through HMM-search using TBtools and the Pfam database.Physicochemical properties of the WRKY family proteins were analyzed with ExPASy-Prot-Param.Multiple comparison analysis and construction of phylogenetic trees of WRKY conserved structural domain sequences of M.sieversii and Arabidopsis thaliana were performed using MEGA software.The conserved motifs and structural domains were analyzed via MEME online website and NCBI-CDD.The cis-acting elements within the 2 000 bp upstream region of the WRKY transcription factor genes were predic-ted using PlantCARE,while the collinearity map was generated by MCScanX and visualized with TBtools.Based on the transcriptome data,RT-qPCR was used to analyze the expression patterns of WRKY tran-scription factors in M.sieversii seeds throughout low-temperature sand storage process.[Result]A total of 121 WRKY genes were identified in M.sieversii,encoding proteins with amino acid numbers ranging from 122 to 733 aa,molecular masses of 17.033 1 to 80.055 1 ku,and isoelectric points ranging from 4.75 to 10.06.The phylogenetic tree analysis showed that the 121 members of the WRKY gene family in M.sieversii were divided into three major groups(Group Ⅰ,Ⅱ,and Ⅲ)and seven subgroups(Ⅱa-Ⅱe).Group Ⅰ contained 21 members,Group Ⅲ had 19 members,and Group Ⅱ was the largest group with 82 members,including 5 Ⅱa,14 Ⅱb,30 Ⅱc,19 Ⅱd,and 14 Ⅱe members.The motifs of M.sieversii WRKY family proteins were relatively consistent within each subgroup,while there was some variability between subgroups.Analysis of cis-acting regulatory elements revealed that the upstream promoter region contained elements related to light response,abiotic stress,and low-temperature stress,and that the MsWRKY gene was rich in hormone response related elements.Chromosomal localization analysis showed the WRKY gene members were distributed on 17 chromosomes.Intraspecific collinearity analysis showed 144 pairs of seg-mental duplications in this family,while interspecific collinearity analysis revealed a total of 359 collinearity gene pairs between 103 MsWRKY genes and 99 MdWRKY genes(Malus domestica WRKY).RT-qPCR analysis showed that the expression of MsWRKY17,MsWRKY31,MsWRKY33,MsWRKY51 and MsWRKY53 initially increased and subsequently decreased during prolonged low-temperature sand sto-rage.The validation results showed that the trend of differential expression of the WRKY family during low-temperature sand stratification of the M.sieversii seeds was consistent with the results of the tran-scriptome analysis.[Conclusion]WRKY transcription factors may play a pivotal role in dormancy release process of M.sieversii seeds during low-temperature sand storage stratification.