苹果NF-X1基因家族及盐胁迫下的组织表达模式分析OA

[Objective]The apple transcription factor NF-X1 gene family was used as the research ob-ject to study its expression characteristics in different tissues and the response pattern to salt stress,provi-ding a reference for further research on the salt resistance function of apple rootstocks.[Method]Using the apple rootstock,Malus×robusta,as the test material,bioinformatics methods were used to identify members of the NF-X1 gene family,analyze the basic physicochemical properties,predict the subcellular localization,and perform the phylogeny analysis.The gene structures,conserved domains,conserved mo-tifs,and promoter cis-elements of the MdNF-X1 gene family members were visualized using TBtools.Re-al-time quantitative PCR(RT-qPCR)was used to detect the tissue-specific expression patterns of the MdNF-X1 gene family and its response properties in different tissues under salt stress.[Result]The apple MdNF-X1 gene family comprises four members,MdNF-X1-1,MdNF-X1-2,MdNF-X1-3,and MdNF-X1-4,enco-ding proteins with 1 162,1 138,865 and 830 amino acids,respectively,all predicted to be nuclear in subcel-lular localization.Phylogenetic analysis based on amino acid sequences revealed that the four MdNF-X1 members could be classified into two subgroups,all being most closely related to the grape NF-X1 family.Protein functional domain analysis showed that all MdNF-X1 family members contained the NF-X1-zinc-finger conserved domain,identifying them as zinc-finger transcription factors.Cis-acting element analysis demonstrated that the promoters of MdNF-X1 gene family contained response elements to salt stress,drought stress and response elements including abscisic acid and auxin.RT-qPCR analysis showed that MdNF-X1-1 and MdNF-X1-3 had higher expression in roots;NF-X1-2 had higher and similar expression in roots and lea-ves;MdNF-X1-4 had lower expression in all tissues.Under salt stress,all four MdNF-X1 genes respon-ded in roots,stems,and leaves.Among them,MdNF-X1-1 exhibited the most significant response to salt stress in the roots,with its relative expression exceeding other family members.[Conclusion]The expres-sion of MdNF-X1-1 gene in the apple rootstock Malus×robusta was significantly induced under salt stress,suggesting its involvement in the response regulation of Malus×robusta under salt stress.This pro-vides a basis for further revealing its specific functions in salt stress resistance.