Yao Wenjing, Zhao Kai, Cheng Zihan, Li Xiyan, Zhou Boru, Jiang Tingbo
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China.
Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China.
Front Plant Sci. 2018 Sep 4;9:1121. doi: 10.3389/fpls.2018.01121. eCollection 2018.
NAC domain genes belong to a large plant-specific transcription factor family, which is well-known to be associated with multiple stress responses and plant developmental processes. In this study, we screened differentially expressed genes (DEGs) and detected mRNA abundance of NAC family by RNA-Seq in the poplar leaves under salt stress condition. A total of 276 up-regulated DEGs and 159 down-regulated DEGs were identified to be shared in × and × . Among 170 NAC members, gene was significantly up-regulated in response to salt stress in the two species. Tissue-specific and salt-responsive analyses indicated the expression pattern of gene was spatial and temporal in poplar under salt stress. Particle bombardment results showed subcellular localization of NAC57 was not solely nucleus-targeted. Full-length cDNA sequence of the gene was cloned from × and transformed into . Under salt stress, transgenic overexpressing showed higher seed germination rate, root length, and fresh weight than wild type plants. In addition, the transgenic plants displayed higher superoxide dismutase activity and peroxidase activity, and lower malondialdehyde content and relative electrical conductivity than the wild type under salt stress condition. Furthermore, histochemical staining indicated reactive oxygen species accumulation was lower in the transgenic plants than that in the wild type under salt stress. All the results indicated that the gene plays an important role in salt stress responses.
NAC结构域基因属于一个大型的植物特有的转录因子家族，众所周知，该家族与多种胁迫反应和植物发育过程相关。在本研究中，我们通过RNA测序在盐胁迫条件下的杨树叶片中筛选了差异表达基因（DEGs）并检测了NAC家族的mRNA丰度。在×和×中总共鉴定出276个上调的DEGs和159个下调的DEGs。在170个NAC成员中，基因在这两个物种中对盐胁迫均有显著上调。组织特异性和盐响应分析表明，在盐胁迫下杨树中基因的表达模式具有时空性。粒子轰击结果表明NAC57的亚细胞定位并非仅靶向细胞核。从×中克隆了基因的全长cDNA序列并将其转化到中。在盐胁迫下，过表达的转基因植株比野生型植株表现出更高的种子萌发率、根长和鲜重。此外，在盐胁迫条件下，转基因植株比野生型表现出更高的超氧化物歧化酶活性和过氧化物酶活性，以及更低的丙二醛含量和相对电导率。此外，组织化学染色表明在盐胁迫下转基因植株中的活性氧积累比野生型低。所有结果表明基因在盐胁迫反应中起重要作用。
