本研究旨在挖掘烟草抗南方根结线虫病程相关基因非表达子NPR1(non-expressor of PR genes)家族成员，并明确其功能。基于拟南芥AtNPR1家族成员蛋白序列，利用生物信息学方法鉴定分析烟草NtNPR1基因家族成员及其特征。通过qRT-PCR检测南方根结线虫侵染后抗病(NC95)、感病(长脖黄)烟草品种Nt-NPR1 家族重要候选抗性基因的相对表达量，采用LC-MS/MS方法对2个品种烟草根系内源水杨酸含量进行检测。结果表明，从普通烟草基因组中共鉴定到12个NtNPR1基因，这些基因被分为3个亚组，同一亚组中NtNPR1家族成员蛋白结构、保守基序的长度和位置都极为相似。编码氨基酸长度范围为462～588，均为亲水性蛋白，均位于细胞核。南方根结线虫侵染抗、感烟草品种后，根系中水杨酸含量、NtNPR1基因家族成员表达量在抗病品种中均升高，在感病品种中则降低，其中NtNPR6的变化最为明显。综上，NPR1基因与烟草南方根结线虫抗性密切相关，NtNPR6基因可作为烟草响应南方根结线虫胁迫的重要基因。
Identification of Tobacco NPR1 Gene Family and Expression Analysis Under Meloidogyne incognita Stress
The research was aimed to mining the non-expressor of PR genes(NPR1)family members in-volved in tobacco resistance to the Meloidogyne incognita disease.Members of the tobacco NtNPR1 gene family were identified and analyzed using bioinformatics method based on the protein sequences of AtNPR1 family members in Arabidopsis.Relative expression level of key candidate resistance genes of NtNPR1 family in tobac-co resistant(NC95)and susceptible(Changbohuang,CBH)varieties infected by M.incognita were analyzed by qRT-PCR.The endogenous salicylic acid(SA)content in roots of the two tobacco varieties were measured by LC-MS/MS.The results showed that a total of 12 NtNPR1 genes were identified from the genome of com-mon tobacco,which were classified into three subgroups.Within each subgroup,the protein structure and con-served motif length and position of NtNPR1 family members were highly similar.The length of encoded amino acids ranged between 462 and 588 aa,and all of them were hydrophilic and localized in nucleus.After being infected with M.incognita,the SA content and expression level of NtNPR1 family members in roots increased in the resistant variety and decreased in the susceptible variety,among which,NtNPR6 changed the most ob-viously.In conclusion,the NPR1 gene is closely related to tobacco resistance to M.incognita,and the Nt-NPR6 gene could be used as a critical gene in response to M.incognita stress.
国家科技期刊平台
