植物为保护自身免受病毒攻击进化出了多种抗病毒防御途径 (Wu et al., 2024)，其中最常见是RNA干扰（RNA interference, RNAi）介导的抗病毒免疫。RNAi通路的关键组分包括DCLs（Dicer-like proteins）、AGOs（Argonaute proteins）、RDR6（RNA-Dependent RNA Polymerase 6）和SGS3（Suppressor of Gene Silencing 3）等蛋白。当正义链RNA病毒基因组发生复制时产生双链RNA被植物DCLs蛋白所识别并切割成21–24 nt的小干扰RNA（siRNA），siRNA被装载到AGOs蛋白中形成RISC复合体（RNA-induced silencing complex），进而靶标病毒RNA诱发RNA沉默，siRNA进一步通过SGS3和RDR6相分离形式的小体（siRNA body）扩增出大量次级小RNA以放大RNA沉默的信号，最终实现RNA沉默介导的抗病毒防御。虽然RNAi通路中的关键组分如DCLs、AGOs及SGS3等蛋白已被广泛研究，但是否有其他蛋白参与调控RNAi仍需深入挖掘。
附：
中国农业大学张永亮课题组主要从事植物病毒致病的分子机制和宿主抗病毒免疫研究。近年来合作开发了用于植物中互作蛋白研究的邻近标记技术（Zhang et al., 2019, Nature Communications; Yang et al., 2021, Plant Communications; Zhang et al., 2020, Journal of Visualized Experiments）。在此基础上，鉴定了多个在植物病毒致病和抗病毒免疫中发挥功能的新组分（Zhang et al., 2023a, PNAS; Zhang et al., 2024, Molecular Plant; Zhang et al., 2023b, Plant Cell; Zhang et al., 2019, Nature Communications）, 为深入理解植物病毒与宿主互作提供了新的科学数据，也为植物抗病毒遗传改良提供了潜在的基因资源。
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文章来源：植物生物技术Pbj
