Zhao Jing, Yang Yuheng, Yang Donghe, Cheng Yulin, Jiao Min, Zhan Gangming, Zhang Hongchang, Wang Junyi, Zhou Kai, Huang Lili, Kang Zhensheng
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University Yangling, China.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Science, Northwest A&F University Yangling, China.
Front Plant Sci. 2016 Nov 30;7:1822. doi: 10.3389/fpls.2016.01822. eCollection 2016.
Wheat stripe rust, caused by f. sp. (), is one of the most devastating diseases of wheat in China. Rapid change to virulence following release of resistant cultivars necessitates ongoing discovery and exploitation of new resistance resources. Considerable effort has been directed at non-host resistance (NHR) which is believed to be durable. In the present study we identified rice mutant (compromised resistance to rust 1) that exhibited compromised NHR to . Compared with wild type rice variety Nipponbare, mutant displayed a threefold increase in penetration rate by , and enhanced hyphal growth. The pathogen also developed haustoria in mesophyll cells, but failed to sporulate. The response to the adapted rice pathogen was unchanged in relative to the wild type. Several defense-related genes involved in the SA- and JA-mediated defense pathways response and in phytoalexin synthesis (such as , , and ) were more rapidly and strongly induced in infected leaves than in the wild type, suggesting that other layers of defense are still in effect. Genetic analysis and mapping located the mutant loci at a region between markers ID14 and RM25792, which cover about 290 kb genome sequence on chromosome 10. Further fine mapping and cloning of the locus should provide further insights into NHR to rust fungi in rice, and may reveal new strategies for improving rust resistance in wheat.
小麦条锈病由小麦条锈菌（Puccinia striiformis f. sp. tritici）引起，是中国小麦最具毁灭性的病害之一。抗性品种发布后毒力的快速变化使得持续发现和利用新的抗性资源成为必要。大量研究致力于非寄主抗性（NHR），人们认为它具有持久性。在本研究中，我们鉴定出水稻突变体（对锈病抗性受损1），其对小麦条锈菌表现出受损的非寄主抗性。与野生型水稻品种日本晴相比，该突变体小麦条锈菌的侵入率增加了两倍，且菌丝生长增强。病原菌还在突变体叶肉细胞中形成吸器，但未能产生孢子。相对于野生型，突变体对适应的水稻病原菌稻瘟病菌（Magnaporthe oryzae）的反应没有变化。一些参与水杨酸（SA）和茉莉酸（JA）介导的防御途径反应以及植物抗毒素合成的防御相关基因（如PAL、PR1和PR5）在感染突变体叶片中比野生型叶片中诱导更快、更强，这表明其他防御层仍然有效。遗传分析和定位将突变位点定位于标记ID14和RM25792之间的区域，该区域覆盖10号染色体上约290 kb的基因组序列。对该位点的进一步精细定位和克隆应该能为水稻对锈菌的非寄主抗性提供进一步的见解，并可能揭示提高小麦锈病抗性的新策略。
