Department of Plant Pathology, Faculty of Agricultural Sciences and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Agronomy and Plant Breeding Department, Faculty of Agriculture, Shahrood University of Technology, Semnan, Iran.
PLoS One. 2024 Oct 4;19(10):e0308116. doi: 10.1371/journal.pone.0308116. eCollection 2024.
Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), one of the most economically destructive wheat foliar diseases. In this study, we explore the physiological and molecular changes elicited in two wheat cultivars with divergent responses (Taichung 29 = susceptible, and Shafir = resistant) upon infection by Z. tritici. Our aim is to uncover novel insights into the intricate mechanisms that govern wheat defense against Z. tritici infection. Our quantitative histopathological study showed that H2O2 accumulated in the resistant cultivar to a higher degree compared to the susceptible cultivar at the biotrophic and switching phase. Additionally, we combined qPCR with a targeted quantitative HPLC technique to evaluate the expression profiles of 13 defense-related genes and profile the polyphenolic compounds induced differentially in the STB susceptible and resistant cultivar. Our finding indicated that five out of 13 genes were strongly up-regulated in the resistant cultivar compared with that of the susceptible one at eight days post-inoculation (dpi), corresponding to the transition phase present in the infection process of Z. tritici. Finally, our targeted HPLC analysis demonstrated that the traced phenolic compounds were highly elevated in the susceptible cultivar infected by Z. tritici compared with that of the resistant cultivar. In conclusion, our comprehensive analysis unveils a robust defense response in the resistant wheat cultivar Shafir, characterized by heightened H2O2 accumulation, significant up-regulation of key defense-related genes during the transition phase, and a distinct profile of polyphenolic compounds, shedding light on the intricate mechanisms contributing to its resistance against Z. tritici, thereby providing valuable insights for the development of more resilient wheat varieties.
小麦叶锈病是由禾旋孢腔菌引起的，是小麦叶片最具破坏性的病害之一。本研究以两种感病性不同（台中 29=感病，沙斐尔=抗病）的小麦品种为材料，研究禾旋孢腔菌侵染后小麦的生理和分子变化，旨在深入了解禾旋孢腔菌侵染小麦过程中复杂的防御机制。定量组织病理学研究表明，在亲和和转变阶段，抗病品种中 H2O2 的积累量高于感病品种。此外，我们结合 qPCR 和靶向定量 HPLC 技术，评估了 13 个防御相关基因的表达谱，并分析了禾旋孢腔菌感病和抗病品种中诱导的多酚化合物的差异表达。结果表明，在侵染过程的转变阶段，有 5 个基因在抗病品种中的表达量显著高于感病品种。最后，我们的靶向 HPLC 分析表明，禾旋孢腔菌侵染感病品种后，追踪到的酚类化合物含量明显高于抗病品种。综上所述，本研究全面分析揭示了抗病小麦品种沙斐尔的强烈防御反应，表现为 H2O2 积累增加、关键防御相关基因在转变阶段的显著上调以及多酚化合物的特征性表达谱，阐明了其对禾旋孢腔菌的抗性机制，为培育更具抗性的小麦品种提供了有价值的信息。
