Jin Tongtong, Yin Jinlong, Wang Tao, Xue Song, Li Bowen, Zong Tingxuan, Yang Yunhua, Liu Hui, Liu Mengzhuo, Xu Kai, Wang Liqun, Xing Guangnan, Zhi Haijian, Li Kai
National Key Laboratory for Crop Genetics and Germplasm Enhancement, Key Laboratory of Biology and Genetic Improvement of Soybean-Ministry of Agriculture, National Center for Soybean Improvement, Nanjing Agricultural University, Nanjing, 210095, China.
Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
J Integr Plant Biol. 2023 Mar;65(3):838-853. doi: 10.1111/jipb.13401. Epub 2022 Dec 31.
Soybean mosaic virus (SMV) is one of the most devastating viral pathogens of soybean (Glycine max (L.) Merr). In total, 22 Chinese SMV strains (SC1-SC22) have been classified based on the responses of 10 soybean cultivars to these pathogens. However, although several SMV-resistance loci in soybean have been identified, no gene conferring SMV resistance in the resistant soybean cultivar (cv.) Kefeng No.1 has been cloned and verified. Here, using F -derived F (F ) and recombinant inbred line (RIL) populations from a cross between Kefeng No.1 and susceptible soybean cv. Nannong 1138-2, we localized the gene in Kefeng No.1 that mediated resistance to SMV-SC3 strain to a 90-kb interval on chromosome 2. To study the functions of candidate genes in this interval, we performed Bean pod mottle virus (BPMV)-induced gene silencing (VIGS). We identified a recombinant gene (which we named R K) harboring an internal deletion of a genomic DNA fragment partially flanking the LOC100526921 and LOC100812666 reference genes as the SMV-SC3 resistance gene. By shuffling genes between infectious SMV DNA clones based on the avirulent isolate SC3 and virulent isolate 1129, we determined that the viral protein P3 is the avirulence determinant mediating SMV-SC3 resistance on Kefeng No.1. P3 interacts with RNase proteins encoded by R K, LOC100526921, and LOC100812666. The recombinant R K conveys much higher anti-SMV activity than LOC100526921 and LOC100812666, although those two genes also encode proteins that inhibit SMV accumulation, as revealed by gene silencing in a susceptible cultivar and by overexpression in Nicotiana benthamiana. These findings demonstrate that R K mediates the resistance of Kefeng No.1 to SMV-SC3 and that SMV resistance of soybean is determined by the antiviral activity of RNase proteins.
大豆花叶病毒（SMV）是大豆（Glycine max (L.) Merr）最具毁灭性的病毒病原体之一。根据10个大豆品种对这些病原体的反应，总共已鉴定出22个中国SMV株系（SC1 - SC22）。然而，尽管已在大豆中鉴定出几个抗SMV位点，但在抗病大豆品种科丰1号中，尚未克隆和验证赋予抗SMV能力的基因。在此，我们利用科丰1号与感病大豆品种南农1138 - 2杂交产生的F衍生的F（F）和重组自交系（RIL）群体，将科丰1号中介导对SMV - SC3株系抗性的基因定位到2号染色体上一个90 kb的区间。为了研究该区间内候选基因的功能，我们进行了菜豆荚斑驳病毒（BPMV）诱导的基因沉默（VIGS）。我们鉴定出一个重组基因（命名为RK），其基因组DNA片段内部缺失，该片段部分侧翼为参考基因LOC100526921和LOC100812666，此重组基因即为抗SMV - SC3的基因。通过基于无毒分离株SC3和有毒分离株1129的感染性SMV DNA克隆之间的基因改组，我们确定病毒蛋白P3是介导科丰1号对SMV - SC3抗性的无毒决定因子。P3与RK、LOC100526921和LOC100812666编码的核糖核酸酶蛋白相互作用。重组RK比LOC100526921和LOC100812666具有更高的抗SMV活性，尽管在感病品种中的基因沉默以及在本氏烟草中的过表达表明，这两个基因也编码抑制SMV积累的蛋白。这些发现表明RK介导了科丰1号对SMV - SC3的抗性，并且大豆对SMV的抗性由核糖核酸酶蛋白的抗病毒活性决定。
