Institute of Crop Science and Resource Conservation (INRES), Molecular Phytomedicine, University of Bonn, INRES, Bonn, Germany.
Department of Plant Pathology, Faculty of Agriculture, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh.
Mol Plant Pathol. 2022 Jul;23(7):1048-1059. doi: 10.1111/mpp.13210. Epub 2022 Mar 29.
Cyst nematodes (CNs) are an important group of root-infecting sedentary endoparasites that severely damage many crop plants worldwide. An infective CN juvenile enters the host's roots and migrates towards the vascular cylinder, where it induces the formation of syncytial feeding cells, which nourish the CN throughout its parasitic stages. Here, we examined the role of glutathione (l-γ-glutamyl-l-cysteinyl-glycine) in Arabidopsis thaliana on infection with the CN Heterodera schachtii. Arabidopsis lines with mutations pad2, cad2, or zir1 in the glutamate-cysteine ligase (GSH1) gene, which encodes the first enzyme in the glutathione biosynthetic pathway, displayed enhanced CN susceptibility, but susceptibility was reduced for rax1, another GSH1 allele. Biochemical analysis revealed differentially altered thiol levels in these mutants that was independent of nematode infection. All glutathione-deficient mutants exhibited impaired activation of defence marker genes as well as genes for biosynthesis of the antimicrobial compound camalexin early in infection. Further analysis revealed a link between glutathione-mediated plant resistance to CN infection and the production of camalexin on nematode infection. These results suggest that glutathione levels affect plant resistance to CN by fine-tuning the balance between the cellular redox environment and the production of compounds related to defence against infection.
胞囊线虫（CNs）是一组重要的根寄生固着内寄生虫，它们严重损害了全球许多作物。一个感染性的 CN 幼虫进入宿主的根部并向维管束迁移，在那里它诱导合胞取食细胞的形成，这些细胞在 CN 的整个寄生阶段为其提供营养。在这里，我们研究了拟南芥中谷胱甘肽（l-γ-谷氨酰基-l-半胱氨酸-glycine）在感染 CN 异皮科线虫中的作用。谷氨酸半胱氨酸连接酶（GSH1）基因中的 pad2、cad2 或 zir1 突变的拟南芥系，该基因编码谷胱甘肽生物合成途径中的第一个酶，对 CN 的易感性增强，但另一个 GSH1 等位基因 rax1 的易感性降低。生化分析显示这些突变体中硫醇水平的差异改变，这与线虫感染无关。所有谷胱甘肽缺乏突变体在感染早期表现出防御标记基因和抗菌化合物 camalexin 生物合成基因的激活受损。进一步的分析表明，谷胱甘肽介导的植物对 CN 感染的抗性与线虫感染时 camalexin 的产生之间存在联系。这些结果表明，谷胱甘肽水平通过微调细胞氧化还原环境与与抗感染相关的化合物的产生之间的平衡来影响植物对 CN 的抗性。
