Dong Jia, Zielinski Raymond E, Hudson Matthew E
Department of Crop Sciences, University of Illinois Urbana-Champaign, Champaign, IL, USA.
Department of Plant Biology, University of Illinois Urbana-Champaign, Champaign, IL, USA.
Plant J. 2020 Oct;104(2):318-331. doi: 10.1111/tpj.14923. Epub 2020 Aug 6.
Soybean cyst nematode (SCN; Heterodera glycines) is the largest pathogenic cause of soybean yield loss. The Rhg1 locus is the most used and best characterized SCN resistance locus, and contains three genes including one encoding an α-SNAP protein. Although the Rhg1 α-SNAP is known to play an important role in vesicle trafficking and SCN resistance, the protein's binding partners and the molecular mechanisms underpinning SCN resistance remain unclear. In this report, we show that the Rhg1 α-SNAP strongly interacts with two syntaxins of the t-SNARE family (Glyma.12G194800 and Glyma.16G154200) in yeast and plants; importantly, the genes encoding these syntaxins co-localize with SCN resistance quantitative trait loci. Fluorescent visualization revealed that the α-SNAP and the two interacting syntaxins localize to the plasma membrane and perinuclear space in both tobacco epidermal and soybean root cells. The two syntaxins and their two homeologs were mutated, individually and in combination, using the CRISPR-Cas9 system in the SCN-resistant Peking and SCN-susceptible Essex soybean lines. Peking roots with deletions introduced into syntaxin genes exhibited significantly reduced resistance to SCN, confirming that t-SNAREs are critical to resisting SCN infection. The results presented here uncover a key step in the molecular mechanism of SCN resistance, and will be invaluable to soybean breeders aiming to develop highly SCN-resistant soybean varieties.
大豆胞囊线虫（SCN；大豆异皮线虫）是导致大豆产量损失的最大致病因素。Rhg1位点是最常用且特征最明确的SCN抗性位点，包含三个基因，其中一个编码α-SNAP蛋白。尽管已知Rhg1 α-SNAP在囊泡运输和SCN抗性中起重要作用，但其蛋白结合伙伴以及支撑SCN抗性的分子机制仍不清楚。在本报告中，我们表明Rhg1 α-SNAP在酵母和植物中与t-SNARE家族的两种 syntaxin蛋白（Glyma.12G194800和Glyma.16G154200）强烈相互作用；重要的是，编码这些syntaxin蛋白的基因与SCN抗性数量性状位点共定位。荧光可视化显示，α-SNAP和两种相互作用的syntaxin蛋白定位于烟草表皮细胞和大豆根细胞的质膜和核周空间。使用CRISPR-Cas9系统，分别或联合突变了SCN抗性品种北京黑豆和SCN感病品种埃塞克斯大豆品系中的两种syntaxin蛋白及其两个同源基因。syntaxin基因发生缺失的北京黑豆根系对SCN的抗性显著降低，证实t-SNAREs对抵抗SCN感染至关重要。本文给出的结果揭示了SCN抗性分子机制中的关键步骤，对于旨在培育高抗SCN大豆品种的大豆育种者而言将具有极高价值。
