He Yu, Feng Lihua, Jiang Yun, Zhang Lianquan, Yan Jun, Zhao Gang, Wang Jirui, Chen Guoyue, Wu Bihua, Liu Dengcai, Huang Lin, Fahima Tzion
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Wenjiang 611130, China.
Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, China.
Pathogens. 2020 Mar 13;9(3):212. doi: 10.3390/pathogens9030212.
Stripe rust, caused by f. sp. (), is a devastating fungal disease of wheat. The wild emmer gene, (), which confers a strong broad-spectrum resistance to isolates, is composed of kinase and pseudokinase domains. The analysis of 361 wild emmer accessions from a wide range of natural habitats confirms that functional is distributed mainly along a narrow axis from Mt. Carmel to Mt. Hermon regions, in the northern part of Israel, where environmental conditions are favorable to the onset of stripe rust. An analysis of full-length DNA sequences from 49 wild emmer accessions identified three haplotypes and extremely low nucleotide diversity (π = 0.00002). The sequence diversity of is 9.5 times lower than that of broad-spectrum partial resistance gene (π = 0.00019), and both are in sharp contrast to the high level of nucleotide diversity previously reported for race-specific resistance genes (e.g., and ). However, the nonfunctional sequences possess high level of nucleotide diversity (π = 0.07). These results may reflect the different resistance mechanisms and the different evolutionary processes that shaped these resistance genes. was absent in 189 Chinese wheat landraces and was present in only 1.02% of the 583 tested modern Chinese wheat cultivars. These results corroborate our previous results showing that was absent in 94% of a worldwide collection of 513 wheat cultivars, therefore indicating the importance of in wheat stripe rust resistance breeding programs in China and elsewhere around the globe.
条锈病由小麦条锈菌（Puccinia striiformis f. sp. tritici）引起，是小麦的一种毁灭性真菌病害。野生二粒小麦基因YrAS2388对条锈菌分离株具有强大的广谱抗性，它由激酶和假激酶结构域组成。对来自广泛自然栖息地的361份野生二粒小麦种质资源的分析证实，功能性YrAS2388主要沿着以色列北部从卡梅尔山到赫尔蒙山地区的一条狭窄轴线分布，该地区的环境条件有利于条锈病的发生。对49份野生二粒小麦种质资源的全长YrAS2388 DNA序列分析确定了三种单倍型，且核苷酸多样性极低（π = 0.00002）。YrAS2388的序列多样性比广谱部分抗性基因Lr34（π = 0.00019）低9.5倍，两者均与先前报道的小种特异性抗性基因（如Yr10和Lr21）的高水平核苷酸多样性形成鲜明对比。然而，无功能的YrAS2388序列具有高水平的核苷酸多样性（π = 0.07）。这些结果可能反映了塑造这些抗性基因的不同抗性机制和不同进化过程。YrAS2388在189份中国小麦地方品种中不存在，在583份测试的现代中国小麦品种中仅占1.02%。这些结果证实了我们之前的结果，即在全球513个小麦品种的收集样本中，94%没有YrAS2388，因此表明YrAS2388在中国和全球其他地方的小麦条锈病抗性育种计划中的重要性。
