Zhang Ling, Castell-Miller Claudia, Dahl Stephanie, Steffenson Brian, Kleinhofs Andris
Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164, USA.
Funct Integr Genomics. 2008 Aug;8(3):187-98. doi: 10.1007/s10142-007-0069-0. Epub 2008 Jan 15.
The dominant barley stem rust resistance gene Rpg1 confers resistance to many but not all pathotypes of the stem rust fungus Puccinia graminis f. sp. tritici (Pgt). Transformation of Rpg1 into susceptible cultivar Golden Promise rendered the transgenic plants resistant to Pgt pathotype MCC but not to Pgt pathotype QCC. Our objective was to identify genes that are induced/repressed during the early stages of pathogen infection to elucidate the molecular mechanisms and role of Rpg1 in defense. A messenger ribonucleic acid expression analysis using the 22K Barley1 GeneChip was conducted in all pair-wise combinations of two isolines (cv. Golden Promise and Rpg1 transgenic line G02-448F-3R) and two Pgt pathotypes (MCC and QCC) across six time points. Analysis showed that a total of 34 probe sets exhibited expression pattern differences between Golden Promise (susceptible) and G02-448F-3R (resistant) infected with Pgt-MCC. A total of 14 probe sets exhibited expression pattern differences between Pgt-MCC (avirulent) and Pgt-QCC (virulent) inoculated onto G02-448F-3R. These differentially expressed genes were activated during the early infection process, before the hypersensitive response or fungal growth inhibition occurred. Our analysis provides a list of candidate signaling components, which can be analyzed for function in Rpg1-mediated disease resistance.
大麦主要的抗秆锈病基因Rpg1对秆锈病菌小麦秆锈菌（Pgt）的许多致病型具有抗性，但并非对所有致病型都有抗性。将Rpg1导入感病品种Golden Promise后，转基因植株对Pgt致病型MCC具有抗性，但对Pgt致病型QCC没有抗性。我们的目标是鉴定在病原体感染早期被诱导/抑制的基因，以阐明Rpg1在防御中的分子机制和作用。使用22K大麦1基因芯片对两个近等基因系（品种Golden Promise和Rpg1转基因系G02-448F-3R）和两种Pgt致病型（MCC和QCC）在六个时间点的所有两两组合进行了信使核糖核酸表达分析。分析表明，在感染Pgt-MCC的Golden Promise（感病）和G02-448F-3R（抗病）之间，共有34个探针集表现出表达模式差异。在接种到G02-448F-3R上的Pgt-MCC（无毒）和Pgt-QCC（有毒）之间，共有14个探针集表现出表达模式差异。这些差异表达基因在早期感染过程中被激活，早于超敏反应或真菌生长抑制的发生。我们的分析提供了一份候选信号成分清单，可对其在Rpg1介导的抗病性中的功能进行分析。
