First, second, third, fourth, fifth, eighth, and ninth authors: Plant Pathology, University of Minnesota, St. Paul; sixth author: CSIRO Agriculture and Food, ACT, Australia; seventh author: The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, U.K.; eighth author: Cereal Disease Laboratory, United States Department of Agriculture-Agricultural Research Service, St. Paul, MN, USA; and ninth author: Stakman-Borlaug Center for Sustainable Plant Health, University of Minnesota, St. Paul.
Phytopathology. 2018 Dec;108(12):1443-1454. doi: 10.1094/PHYTO-03-18-0084-R. Epub 2018 Oct 31.
Oat crown rust caused by Puccinia coronata f. sp. avenae is the most destructive foliar disease of cultivated oat. Characterization of genetic factors controlling resistance responses to Puccinia coronata f. sp. avenae in nonhost species could provide new resources for developing disease protection strategies in oat. We examined symptom development and fungal colonization levels of a collection of Brachypodium distachyon and B. hybridum accessions infected with three North American P. coronata f. sp. avenae isolates. Our results demonstrated that colonization phenotypes are dependent on both host and pathogen genotypes, indicating a role for race-specific responses in these interactions. These responses were independent of the accumulation of reactive oxygen species. Expression analysis of several defense-related genes suggested that salicylic acid and ethylene-mediated signaling but not jasmonic acid are components of resistance reaction to P. coronata f. sp. avenae. Our findings provide the basis to conduct a genetic inheritance study to examine whether effector-triggered immunity contributes to nonhost resistance to P. coronata f. sp. avenae in Brachypodium spp.
由燕麦冠锈菌引起的燕麦冠锈病是栽培燕麦最具破坏性的叶部病害。鉴定非寄主物种中控制对燕麦冠锈菌抗性反应的遗传因子可为燕麦病害防治策略提供新资源。我们检测了受北美三种燕麦冠锈菌分离物侵染的一组短柄草和杂交短柄草(Brachypodium distachyon and B. hybridum) 品种的症状发展和真菌定殖水平。结果表明，定殖表型取决于宿主和病原体基因型，表明在这些相互作用中存在特定小种的反应作用。这些反应与活性氧的积累无关。几种防御相关基因的表达分析表明，水杨酸和乙烯介导的信号转导而不是茉莉酸是燕麦冠锈菌抗性反应的组成部分。我们的研究结果为进行遗传遗传研究提供了基础，以检验效应触发免疫是否有助于短柄草属非寄主对燕麦冠锈菌的抗性。
