烟草BTB/POZ蛋白家族的鉴定及其在抗马铃薯Y病毒中的作用

Identification of BTB/POZ protein family in Nicotiana tabacum and its role in resistance to potato virus Y(PVY)

马铃薯Y病毒(potato virus Y,PVY)侵染烟草(Nicotiana tabacum)会引起烟草脉带病,造成烟叶品质下降。broad complex,tramtrack,and bric-à-brac/pox virus and zinc finger(BTB/POZ)是动植物体内广泛存在的蛋白质家族,在植物生长和发育的各个环节都起着非常重要的作用。本研究鉴定到90个烟草BTB/POZ家族蛋白,对应71个基因。在这些蛋白质的序列中,识别到9种保守基序(motif),并根据其出现顺序将BTB/POZ家族成员划分至6个亚家族。结构域分析表明,BTB/POZ同一亚家族成员的结构域具有一致性。对BTB/POZ蛋白的三维构象进行预测发现,所有亚家族成员结构都以α螺旋为主,同一亚家族成员的三维构象相似。烟草品种K326和突变体M867(抗PVY)的BTB/POZ家族基因表达模式分析显示,叶片接种PVY后,NtBTB2M、NtBTB2K、NtBTB2L、NtBTB6E基因的表达丰度显著增加,这可能与烟草M867对PVY的抗性较强有关。顺式作用元件分析显示,NtBTB2K、NtBTB2L、NtBTB2M和NtBTB6E基因的上游2000 bp区域内含有若干逆境响应相关元件,包括水杨酸响应元件、MYB结合位点等,可能和这些基因的上调表达有关。本研究为BTB/POZ蛋白的功能研究提供了理论依据,为烟草抗病育种提供了一定参考。

The infection of Nicotiana tabacum with potato virus Y(PVY)can cause tobacco vein disease,leading to a decrease in the tobacco leaf quality.The broad complex,tramtrack,and bric-à-brac/pox virus and zinc finger(BTB/POZ)family exists widely in plants and animals.It plays a very important role in various stages of plant growth and development.In this study,90 proteins in the BTB/POZ family of N.tabacum were identified,corresponding to 71 genes.Among these protein sequences,nine conserved motifs were identified,and the members of the BTB/POZ family were divided into six subfamilies according to the order of their appearance.Domain analysis showed that the domains of members of the same subfamily in BTB/POZ are consistent.The three-dimensional(3D)conformation of the BTB/POZ protein was predicted based on the amino acid sequence.All the members of the subfamily are mainly structured withαhelixes,and the 3D conformations of members of the same subfamily are similar.Analysis of the BTB/POZ family gene expression patterns of N.tabacum K326 and mutant M867(anti-PVY)showed that the expression levels of NtBTB2K,NtBTB2L,NtBTB2M and NtBTB6E increased significantly after inoculation with PVY,which may be related to the strong resistance of N.tabacum M867 to PVY.Cis-acting element analysis showed that the 2000 bp upstream region of NtBTB2K,NtBTB2L,NtBTB2M and NtBTB6E contained several stress responsive elements,including TCA-element and MYB-binding site,which may be related to the upregulated expression of these genes.This study provides a theoretical basis for the study of BTB/POZ protein function,and provides a reference for disease resistance of tobacco breeding.