Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, D-06466 Gatersleben, Germany.
Mol Plant Pathol. 2005 Mar 1;6(2):139-51. doi: 10.1111/j.1364-3703.2005.00271.x.
SUMMARY The shoot epidermis of plants is of prime importance for host and non-host defence against a large number of fungal diseases, including powdery mildew of barley, caused by Blumeria graminis (DC.) E.O. Speer f.sp. hordei. In order to understand better the mechanisms within the epidermis leading to susceptibility as well as durable host resistance, we characterized the transcriptome of two Blumeria-attacked, near-isogenic barley lines of cv Ingrid differing in the presence or absence of the mlo5 resistance gene. A cDNA array was established containing 3128 unique sequences from pathogen-attacked, resistant barley epidermis, which was hybridized with cDNA probes from pathogen-challenged epidermis. Expression analysis resulted in the identification of 311 candidate genes that were differentially expressed in a reproducible manner between control and inoculated epidermis. Among the up-regulated genes were 18 of fungal origin. The amplitude of differential host gene expression was generally higher in the presence of the mlo5 resistance gene as compared with a susceptible interaction. This suggests that mlo-mediated resistance is based on multiple defence compounds and mechanisms once pathogen-derived molecular patterns have been recognized, which yields a possible explanation for the durability of the phenomenon in the field.
摘要 植物的茎表皮对于抵抗许多真菌病，包括大麦白粉病，具有重要意义，这些真菌病是由布氏白粉菌（DC.）E.O. Speer f.sp. hordei 引起的。为了更好地理解导致易感性和持久宿主抗性的表皮内机制，我们对两个近等基因大麦系 Ingrid 的茎表皮进行了转录组特征分析，这两个系在是否存在 mlo5 抗性基因方面存在差异。建立了一个 cDNA 阵列，其中包含来自受病原体攻击的抗性大麦表皮的 3128 个独特序列，并用来自受病原体攻击的表皮的 cDNA 探针进行杂交。表达分析确定了 311 个候选基因，这些基因在对照和接种表皮之间以可重复的方式差异表达。上调基因中有 18 个来自真菌。与易感相互作用相比，mlo5 抗性基因存在时，宿主基因表达的差异幅度通常更高。这表明 mlo 介导的抗性基于多种防御化合物和机制，一旦识别出病原体衍生的分子模式，就会产生该现象在田间持久存在的可能解释。
