Molecular characterization of the ERF family in susceptible poplar infected by virulent Melampsora larici-populina
Molecular characterization of the ERF family in susceptible poplar infected by virulent Melampsora larici-populina
复制标题
强毒落叶松杨霉感染易感杨树中 ERF 家族的分子特征
DOI：
10.1016/j.pmpp.2019.101437
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发表时间：
2019-12-01
影响因子：
2.7
通讯作者：
Wang, Jianan
中科院分区：
文献类型：
--
作者：
Chen, Qiaoli;Wang, Zhiying;Wang, Jianan
杨树枯萎病菌在世界范围内引起严重的杨树叶部病害，称为锈病。乙烯反应因子(ERF)家族是转录因子家族中最大的家族之一，被认为在调节植物抗病相关网络中起着至关重要的作用。为了研究与杨树锈病抗性相关的ERF基因的转录谱，以对杨树锈病E4小种敏感的黑杨×美洲黑杨(PND)为研究对象。对接种E4(锈菌+)和不接种E4(锈菌)PND叶片的混合时间点的数字基因表达(DGE)文库进行了研究，共获得143个PND-ERF基因，其中41个PND-ERF基因的转录水平发生了变化。RT-qPCR结果表明，当植株处于4dpi时，这些PND-ERF基因的转录水平大多降低或没有变化。然后对4dpi的锈病+或锈病-PND叶片进行转录组测序，预测和分析了PND-ERF及其靶基因的相互作用网络。根据转录组测序结果，93个PND-ERF基因在锈病+PND叶片和锈病-PND叶片中的转录水平存在显著差异，其中21个基因表达上调，72个基因表达下调。此外，在216个相互作用中，有24个PND-ERF对199个靶基因进行了调控。其中只有31个靶基因被激活，70个靶基因没有变化，其余98个靶基因被抑制。GO富集分析表明，与其转录水平相比，锈病+PND叶片PND-ERF的大部分抗病相关靶基因表达下调。然而，组蛋白脱乙酰基酶I基因是植物天然免疫的负调节基因，它被转录抑制因子PND-ERF40靶向，在4dpi处显著上调。在4dpi时，大多数PND-ERF基因及其抗病相关靶基因的失活，以及植物天然免疫负调控因子的激活，可能是PND易感性的原因。因此，PND-ERF基因网络在关键时间点的失活应对PND抗性的破坏起作用。
Melampsora larici-populina causes serious poplar foliar diseases called rust worldwide. The ethylene response factor (ERF) family, which is one of the largest groups of transcription factors (TFs) families, is considered to play a crucial role in regulating networks related to plant disease resistance. To investigate the transcript profiles of ERF genes involved in poplar rust resistance, Populus nigra x P. deltoides (Pnd), which is susceptible to the E4 race of M. larici-populina, was selected for this study. Digital gene expression (DGE) libraries of mixed time points of E4-inoculated (rust + ) or E4-free (rust-) Pnd leaves were examined, yielding 143 Pnd-ERF genes of which 41 Pnd-ERF genes had altered transcript levels. RT-qPCR results indicated that transcript levels of these Pnd-ERF genes were mostly reduced or unchanged when plants were at 4 dpi. Then transcriptome sequencing for rust + or rust- Pnd leaves at 4 dpi was performed and interaction network of Pnd-ERFs and their target genes were predicted and analyzed. Based on the results of the transcriptome sequencing, transcript levels of 93 Pnd-ERF genes in rust + Pnd leaves were significantly different from those in rust- Pnd leaves, including 21 upregulated and 72 downregulated genes. In addition, 199 target genes were predicted to be regulated by 24 Pnd-ERFs in 216 interactions. Among them, only 31 target genes were activated, whereas 70 target genes were unchanged and the remaining 98 target genes were repressed. GO enrichment analysis indicated that most disease resistance-related target genes of Pnd-ERFs from rust + Pnd leaves were downregulated compared with their transcript levels in rust- Pnd leaves. Nevertheless, a negative regulator of plant innate immunity, the histone deacetylase I gene, which was targeted by a transcriptional repressor, Pnd-ERF40, was dramatically upregulated at 4 dpi. The inactivation of most Pnd-ERF genes and their disease resistance-related target genes, along with the activation of the negative regulator of plant innate immunity, at 4 dpi might account for the susceptibility of Pnd. Therefore, the inactivation of the Pnd-ERF gene network at the crucial time point should work on the breaking down of the resistance of Pnd.