Upadhyaya Narayana M, Mago Rohit, Panwar Vinay, Hewitt Tim, Luo Ming, Chen Jian, Sperschneider Jana, Nguyen-Phuc Hoa, Wang Aihua, Ortiz Diana, Hac Luch, Bhatt Dhara, Li Feng, Zhang Jianping, Ayliffe Michael, Figueroa Melania, Kanyuka Kostya, Ellis Jeffrey G, Dodds Peter N
Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, Australian Capital Territory, Australia.
Biointeractions and Crop Protection, Rothamsted Research, Harpenden, UK.
Nat Plants. 2021 Sep;7(9):1220-1228. doi: 10.1038/s41477-021-00971-5. Epub 2021 Jul 22.
Stem rust caused by the fungus Puccinia graminis f. sp. tritici (Pgt) is a devastating disease of the global staple crop wheat. Although this disease was largely controlled in the latter half of the twentieth century, new virulent strains of Pgt, such as Ug99, have recently evolved. These strains have caused notable losses worldwide and their continued spread threatens global wheat production. Breeding for disease resistance provides the most cost-effective control of wheat rust diseases. A number of rust resistance genes have been characterized in wheat and most encode immune receptors of the nucleotide-binding leucine-rich repeat (NLR) class, which recognize pathogen effector proteins known as avirulence (Avr) proteins. However, only two Avr genes have been identified in Pgt so far, AvrSr35 and AvrSr50 (refs. ), and none in other cereal rusts. The Sr27 resistance gene was first identified in a wheat line carrying an introgression of the 3R chromosome from Imperial rye. Although not deployed widely in wheat, Sr27 is widespread in the artificial crop species Triticosecale (triticale), which is a wheat-rye hybrid and is a host for Pgt. Sr27 is effective against Ug99 (ref. ) and other recent Pgt strains. Here, we identify both the Sr27 gene in wheat and the corresponding AvrSr27 gene in Pgt and show that virulence to Sr27 can arise experimentally and in the field through deletion mutations, copy number variation and expression level polymorphisms at the AvrSr27 locus.
由真菌小麦秆锈菌（Puccinia graminis f. sp. tritici，Pgt）引起的秆锈病是全球主要粮食作物小麦的一种毁灭性病害。尽管这种病害在20世纪后半叶得到了很大程度的控制，但最近已进化出Pgt的新的毒性菌株，如Ug99。这些菌株已在全球范围内造成了显著损失，其持续传播威胁着全球小麦生产。抗病育种是控制小麦锈病最具成本效益的方法。小麦中已鉴定出许多抗锈基因，其中大多数编码核苷酸结合富含亮氨酸重复序列（NLR）类的免疫受体，这些受体识别被称为无毒（Avr）蛋白的病原体效应蛋白。然而，到目前为止，在Pgt中仅鉴定出两个Avr基因，即AvrSr35和AvrSr50（参考文献），而在其他谷物锈病中尚未鉴定出。Sr27抗性基因最初是在一个携带来自帝国黑麦3R染色体渗入片段的小麦品系中鉴定出来的。尽管Sr27在小麦中未广泛应用，但它在人工作物物种小黑麦（triticale）中广泛存在，小黑麦是小麦-黑麦杂交种，也是Pgt的寄主。Sr27对Ug99（参考文献）和其他近期的Pgt菌株有效。在这里，我们鉴定了小麦中的Sr27基因以及Pgt中相应的AvrSr27基因，并表明对Sr27的毒性可通过AvrSr27位点的缺失突变、拷贝数变异和表达水平多态性在实验和田间产生。
