Molecular Biology of Plant-Microbe Interactions Research Group, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Julia-Lermontowa-Weg 3, 37077, Goettingen, Germany.
Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120, Halle (Saale), Germany.
Plant J. 2021 Feb;105(4):994-1009. doi: 10.1111/tpj.15082. Epub 2020 Dec 25.
IMPORTIN-α3/MOS6 (MODIFIER OF SNC1, 6) is one of nine importin-α isoforms in Arabidopsis that recruit nuclear localization signal-containing cargo proteins to the nuclear import machinery. IMP-α3/MOS6 is required genetically for full autoimmunity of the nucleotide-binding leucine-rich repeat immune receptor mutant snc1 (suppressor of npr1-1, constitutive 1) and MOS6 also contributes to basal disease resistance. Here, we investigated the contribution of the other importin-α genes to both types of immune responses, and we analyzed potential interactions of all importin-α isoforms with SNC1. By using reverse-genetic analyses in Arabidopsis and protein-protein interaction assays in Nicotiana benthamiana, we provide evidence that among the nine α-importins in Arabidopsis, IMP-α3/MOS6 is the main nuclear transport receptor of SNC1, and that IMP-α3/MOS6 is required selectively for autoimmunity of snc1 and basal resistance to mildly virulent Pseudomonas syringae in Arabidopsis.
IMPORTIN-α3/MOS6（SNC1、6 的修饰因子）是拟南芥中 9 种 importin-α 同工型之一，可将含有核定位信号的货物蛋白募集到核输入机制中。IMP-α3/MOS6 在核苷酸结合富含亮氨酸重复免疫受体突变体 snc1（npr1-1 的抑制子，组成型 1）的完全自身免疫中具有遗传作用，MOS6 也有助于基础抗病性。在这里，我们研究了其他 importin-α 基因对这两种免疫反应的贡献，并分析了所有 importin-α 同工型与 SNC1 的潜在相互作用。通过在拟南芥中进行反向遗传学分析和在本氏烟中进行蛋白-蛋白相互作用测定，我们提供的证据表明，在拟南芥的 9 种α-importin 中，IMP-α3/MOS6 是 SNC1 的主要核转运受体，并且 IMP-α3/MOS6 选择性地需要 snc1 的自身免疫和拟南芥中对温和毒力的丁香假单胞菌的基础抗性。
