Little is known about the initial, symptomless (latent) phase of the devastating wheat disease Septoria tritici blotch. However, speculations as to its impact on fungal success and disease severity in the field have suggested that a long latent phase is beneficial to the host and can reduce inoculum build up in the field over a growing season. The winter wheat cultivar Stigg is derived from a synthetic hexaploid wheat and contains introgressions from wild tetraploid wheat Triticum turgidum subsp. dicoccoides, which contribute to cv. Stigg’s exceptional STB resistance, hallmarked by a long latent phase. We compared the early transcriptomic response to Zymoseptoria tritici of cv. Stigg to a susceptible wheat cultivar, to elucidate the mechanisms of and differences in pathogen recognition and disease response in these two hosts. The STB-susceptible cultivar Longbow responds to Z. tritici infection with a stress response, including activation of hormone-responsive transcription factors, post translational modifications, and response to oxidative stress. The activation of key genes associated with these pathways in cv. Longbow was independently observed in a second susceptible wheat cultivar based on an independent gene expression study. By comparison, cv. Stigg is apathetic in response to STB, and appears to fail to activate a range of defence pathways that cv. Longbow employs. Stigg also displays some evidence of sub-genome bias in its response to Z. tritici infection, whereas the susceptible cv. Longbow shows even distribution of Z. tritici responsive genes across the three wheat sub-genomes. We identify a suite of disease response genes that are involved in early pathogen response in susceptible wheat cultivars that may ultimately lead to susceptibility. In comparison, we hypothesise that rather than an active defence response to stave off disease progression, cv. Stigg’s defence strategy is molecular lethargy, or a lower-amplitude of pathogen recognition that may stem from cv. Stigg’s wild wheat-derived ancestry. Overall, we present insights into cv. Stigg’s exceptional resistance to STB, and present key biological processes for further characterisation in this pathosystem.

中文翻译：

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深入了解合成小麦对小麦斑枯病的抗性：少即是多。


对于毁灭性小麦病害小麦壳针孢的初始、无症状（潜伏）阶段知之甚少。然而，对其对田间真菌成功和疾病严重程度影响的推测表明，较长的潜伏期对宿主有益，并且可以减少生长季节田间接种物的积累。冬小麦品种 Stigg 源自合成的六倍体小麦，并含有野生四倍体小麦 Triticum turgidum subsp. 的基因渗入。 dicoccoides，有助于 cv。斯蒂格具有出色的 STB 抵抗力，其特点是潜伏期较长。我们比较了 cv. 小麦发酵壳孢 (Zymoseptoria tritici) 的早期转录组反应。 Stigg对一个易感小麦品种进行了研究，以阐明这两种宿主的病原体识别和疾病反应的机制和差异。 STB易感品种Longbow通过应激反应对小麦小麦感染作出反应，包括激活激素反应性转录因子、翻译后修饰和对氧化应激的反应。简历中与这些途径相关的关键基因的激活。根据一项独立的基因表达研究，在第二个易感小麦品种中独立观察到了长弓病。相比之下，简历。斯蒂格对 STB 反应冷漠，并且似乎无法激活一系列防御途径。长弓雇佣。 Stigg 在对小麦小麦感染的反应中也显示出一些亚基因组偏差的证据，而易感 cv。 Longbow 显示小麦小麦响应基因在三个小麦亚基因组中均匀分布。我们鉴定了一系列疾病反应基因，这些基因参与易感小麦品种的早期病原体反应，最终可能导致易感性。 相比之下，我们假设 cv 不是通过主动防御反应来阻止疾病进展。斯蒂格的防御策略是分子嗜睡，或者可能源于 cv 的较低幅度的病原体识别。斯蒂格的野生小麦血统。总的来说，我们提出了对简历的见解。 Stigg 对 STB 具有出色的抵抗力，并提出了该病理系统进一步表征的关键生物过程。