NAC转录因子因其广泛参与植物逆境应答、细胞代谢及生长发育过程而备受关注。迄今，关于杨树胁迫相关NAC功能及其作用机制的报道非常有限。前期研究中，本课题组从耐旱性增强的PtMKK4过表达转基因杨树中筛选到一组表达上调的NAC基因，进一步比较其在抗逆胡杨和非抗逆毛果杨中对逆境响应模式的差异，发现2个NAC基因（PeSNAC1和PeSNAC2）在胡杨中对干旱或高盐处理高水平应答，而其毛果杨对应同源基因的表达水平变化不明显，暗示其可能与胡杨对干旱、高盐的耐受性密切相关。本课题将确定调控PeSNAC1和PeSNAC2表达的上游信号；全面解析其生物学功能；鉴定其下游靶基因、结合位点及与其相互作用的蛋白质，探明其调控途径。在此基础上，对其中的重要节点进行鉴定、验证，建立PeSNAC1和PeSNAC2的基因调控网络。本项目的完成将为深入理解胡杨抗逆机理提供新资料，同时为杨树抗逆性遗传改良提供理论依据。

NAM, ATAF1,2, and CUC2 (NAC) proteins have received considerable attention, due to their regulation function in many biological processes, including stress response, cell metabolism, and plant growth and development. To date, little is known about the stress-related NAC genes in poplar. In our previous study, we analyzed the differences of the transcriptomes between the transgenic poplar lines overexpressing PtMKK4 and the non-transgneic lines using RNA sequencing technique, and obtained a subset of NAC genes which were up-regulated in the transgenic lines. To judge whether this subset of NAC genes participated in poplar responses to stresses or not, we further compared the expression patterns of these NAC genes in Populus euphratica with those in Populus trichocarpa under diverse stress treatments. The results showed that two NAC genes of Populus euphratica (PeSNAC1 and PeSNAC2) were up-regulated obviously by drought or high salinity treatment, while the expression levels of their homologous genes in Populus trichocarpa showed little changes, indicating that PeSNAC1 and PeSNAC2 may play important roles in the response to drought or high salinity in Populus euphratica. With the help of the established research platforms such as poplar genetic transformation system, protoplast transient expression system, etc., the following research work will be carried out, which includes: determining the upstream signal regulating the expression of PeSNAC1 and PeSNAC2; comprehensively analyzing the functions of PeSNAC1 and PeSNAC2; identifying the downstream target genes and the interacting proteins of PeSNAC1 and PeSNAC2, and ascertaining their regulation pathways. Based on the data obtained, we will build the regulatory networks of PeSNAC1 and PeSNAC2 in Populus euphratica. Our study will provide insights into the molecular resistance mechanisms of Populus euphratica, and lay solid foundations for improving the poplar stress resistance via genetic engineering.