Barley plants can be infected by a variety of fungal pathogens with different lifestyles. The biotrophic Blumeria graminis, necrotrophic Pyrenopora teres, and hemibiotrophic Cochliobolus sativus are economically important pathogens of barley worldwide. Currently, the mechanisms underlying resistance to these diseases are still largely unknown. In the current study, expression patterns of some well-known pathogenesis-related (PR) genes were monitored at early points of infection in resistant and susceptible barley genotypes using quantitative PCR method. Data showed earlier and higher accumulation of PR transcripts in the resistant genotype as compared with the susceptible one, and the expression patterns of the same defense-associated genes were altered in adaptation to each pathogen. The most outstanding differences were observed in PR1 and PR5 genes that were highly activated in resistant plants infected with the hemibiotrophic pathogen rather than the biotrophic and necrotrophic ones. The barley defense response mechanisms against these pathogens could be in agreement with the well-accepted concept that these events are intense in the resistant cultivar. This work might provide useful information for a deeper molecular research on barley defense responses toward pathogens with different lifestyles.

中文翻译：

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不同生活方式的病原真菌攻击的大麦植物的发病机制相关基因反应

大麦植物可以被多种生活方式不同的真菌病原体感染。生物营养的禾谷球藻、坏死性营养的圆球核菌和半生物营养的 Cochliobolus sativus 是世界范围内大麦的重要经济病原体。目前，对这些疾病产生抵抗力的机制在很大程度上仍是未知的。在当前的研究中，使用定量 PCR 方法在抗性和易感大麦基因型的早期感染点监测了一些众所周知的发病机制相关 (PR) 基因的表达模式。数据显示，与易感基因型相比，抗性基因型中 PR 转录本的积累更早且更高，并且相同防御相关基因的表达模式在适应每种病原体时发生了改变。最显着的差异是在 PR1 和 PR5 基因中观察到的，这些基因在被半生物营养病原体感染的抗性植物中被高度激活，而不是在生物营养和坏死营养的植物中。针对这些病原体的大麦防御反应机制可能与广为接受的概念一致，即这些事件在抗性品种中很强烈。这项工作可能为大麦对不同生活方式病原体的防御反应进行更深入的分子研究提供有用的信息。