Chano Víctor, Ferrari Renata Callegari, Domínguez-Flores Tania, Shrestha Karuna, Fussi Barbara, Seidel Hannes, Gailing Oliver, Budde Katharina B
Department of Forest Genetics and Forest Tree Breeding, University of Göttingen, Büsgenweg 2, Göttingen, 37077, Germany.
Center for Integrated Breeding Research (CiBreed), University of Göttingen, Albrecht-Thaer-Weg 3, Göttingen, 37075, Germany.
BMC Plant Biol. 2025 Jan 25;25(1):107. doi: 10.1186/s12870-025-06074-z.
Hymenoscyphus fraxineus, the causal agent of Ash Dieback (ADB), has been introduced to eastern Europe in the 1990s from where it spread causing decline in European ash populations. However, the genetic basis of the molecular response in tolerant and susceptible ash trees to this disease is still largely unknown. We performed RNA-sequencing to study the transcriptomic response to the disease in four ash genotypes (ADB-tolerant FAR3 and FS36, and ADB-susceptible UW1 and UW2), during a time-course of 7, 14, 21, and 28 days post-inoculation, including mock-inoculated trees as control samples for each sampling time point. The analysis yielded 395 and 500 Differentially Expressed Genes (DEGs) along the response for ADB-tolerant FAR3 and FS36, respectively, while ADB-susceptible UW1 and UW2 revealed 194 and 571 DEGs, respectively, with most DEGs found exclusively in just one of the genotypes. DEGs shared between tolerant genotypes FAR3 and FS36, included genes involved in the production of phytoalexins and other secondary metabolites with roles in plant defense. Moreover, we identified an earlier expression of genes involved in both pattern- and effector-triggered immunity (PTI and ETI) in ADB-tolerant genotypes, while in ADB-susceptible genotypes both responses were delayed (late response). Overall, these results revealed different transcriptomic expression patterns not only between ADB-tolerant and ADB-susceptible genotypes, but also within these two groups. This hints to individual responses in the natural tolerance to ADB, possibly revealing diversified strategies across ash genotypes.
梣帚霉（Hymenoscyphus fraxineus）是白蜡树枯梢病（ADB）的病原体，于20世纪90年代被引入东欧，随后在当地传播，导致欧洲白蜡树种群数量减少。然而，耐病和感病白蜡树对这种疾病的分子反应的遗传基础仍 largely unknown。我们进行了RNA测序，以研究四种白蜡树基因型（耐ADB的FAR3和FS36，以及感ADB的UW1和UW2）在接种后7、14、21和28天的病程中对该疾病的转录组反应，包括将 mock-inoculated 树作为每个采样时间点的对照样本。分析分别在耐ADB的FAR3和FS36的反应中产生了395个和500个差异表达基因（DEG），而感ADB的UW1和UW2分别显示了194个和571个DEG，大多数DEG仅在其中一种基因型中发现。耐病基因型FAR3和FS36之间共享的DEG包括参与植保素和其他在植物防御中起作用的次生代谢产物产生的基因。此外，我们在耐ADB的基因型中鉴定出参与模式触发免疫和效应子触发免疫（PTI和ETI）的基因的早期表达，而在感ADB的基因型中，这两种反应均延迟（晚期反应）。总体而言，这些结果不仅揭示了耐ADB和感ADB基因型之间不同的转录组表达模式，而且在这两组内也存在差异。这暗示了对白蜡树枯梢病自然耐受性的个体反应，可能揭示了不同白蜡树基因型的多样化策略。
