目的 研究3代白木香Aquilaria sinensis离体根在盐胁迫条件下的转录因子表达模式差异，对响应盐胁迫的各代转录因子家族差异基因的变化规律进行分析。方法 以组织培养的白木香离体根为材料，采用Illumina Hiseq4000双端PE150测序方法，将所有白木香Unigene序列与植物转录因子数据库（PlantTFDB）进行比对，对盐胁迫组与对照组间的3代差异转录因子进行重点分析。结果 3代白木香离体根转录组测序片段经de novo拼接共获得48 286条Unigene序列，含有1 156个潜在的白木香转录因子，分布于54个转录因子家族。其中bHLH、ERF、NAC家族是富集最多的3个家族。在第1、2、3代盐胁迫白木香根中分别筛选出290、277、349个差异表达转录因子，NAC、MYB以及WRKY家族上调表达的差异表达基因（DEG）数量随胁迫代数增加而增多，而GRAS家族上调表达的DEG数量随胁迫代数增加而减少。3代共有的差异转录因子有70个，其中8个基因的下调表达倍数随盐胁迫代数增加而递增。结论 盐胁迫对白木香转录因子表达影响主要以下调为主。盐胁迫组与对照组的差异转录因子数量随着盐胁迫代数增加而增加。不同转录因子家族基因受盐胁迫诱导表达情况不同，一些基因可能参与了胁迫记忆的传递。该研究有助于在整体水平加深了解白木香转录因子表达特性，为进一步研究白木香胁迫记忆及白木香盐胁迫响应分子机制提供参考。

Objective To study the expression patterns and levels of transcription factors (TFs) in three generations of excised roots of Aquilaria sinensis under salt stress, and analyze the variation of TFs family genes in each generation in response to salt stress. Methods The excised roots of A. sinensis were used as experimental material, using highthroughput sequencing technology (Illumina Hiseq4000), all the unigene sequences were compared with the plant transcription factor database (PlantTFDB), and the three generation differential expressed TFs between the treated and the control group were analyzed. Results A total of 48 286 Unigenes were obtained by de novo splicing from three generation of excised roots of A. sinensis, containing 1 156 potential TFs distributed in 54 TF families. Among them, bHLH, ERF, and NAC were the three most enriched families. Totally, 290, 277, and 349 differentially expressed TFs were respectively screened in three successive generations, which were mainly down-regulated. The expression induced by salt stress were different in each TF family, the numbers of up-regulated DEGs increased in NAC, MYB, and WRKY families, and decreased in GRAS family with the increase of stressed generations. There were 70 common TFs differentially expressed in three generations, and the down-regulated expression multiples of eight genes increased with the increase of salt stress generations. Conclusion The effect of salt stress on the expression of TFs was mainly down-regulatied. The number of differential expressed TFs in the treated and control group increased with the increase of salt stress generations. The expression of different TF family genes was different under salt stress, and some genes might be involved in the transmission of stressful memory. This study is helpful to understand the expression characteristics of TFs at the whole level and provide a reference for further study on the stressful memories and the molecular mechanism of the salt stress response.

R282.12

国家自然科学基金青年基金项目（81102764）；广东省教育厅重点提升平台建设项目—岭南中药资源教育部重点实验室（2014KTSPT016）