Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria.
Plant Cell. 2021 Aug 31;33(8):2523-2537. doi: 10.1093/plcell/koab140.
In the arms race between plants and viruses, two frontiers have been utilized for decades to combat viral infections in agriculture. First, many pathogenic viruses are excluded from plant meristems, which allows the regeneration of virus-free plant material by tissue culture. Second, vertical transmission of viruses to the host progeny is often inefficient, thereby reducing the danger of viral transmission through seeds. Numerous reports point to the existence of tightly linked meristematic and transgenerational antiviral barriers that remain poorly understood. In this review, we summarize the current understanding of the molecular mechanisms that exclude viruses from plant stem cells and progeny. We also discuss the evidence connecting viral invasion of meristematic cells and the ability of plants to recover from acute infections. Research spanning decades performed on a variety of virus/host combinations has made clear that, beside morphological barriers, RNA interference (RNAi) plays a crucial role in preventing-or allowing-meristem invasion and vertical transmission. How a virus interacts with plant RNAi pathways in the meristem has profound effects on its symptomatology, persistence, replication rates, and, ultimately, entry into the host progeny.
在植物和病毒之间的军备竞赛中，几十年来，人们利用两个前沿领域来对抗农业中的病毒感染。首先，许多致病病毒被排除在植物分生组织之外，这使得通过组织培养再生无病毒植物材料成为可能。其次，病毒向宿主后代的垂直传播通常效率低下，从而降低了通过种子传播病毒的危险。大量报道指出存在与分生组织和跨代抗病毒屏障紧密相关的现象，但这些机制仍知之甚少。在这篇综述中，我们总结了目前对将病毒排除在植物干细胞及其后代之外的分子机制的理解。我们还讨论了将分生组织细胞中的病毒入侵与植物从急性感染中恢复的能力联系起来的证据。数十年来在各种病毒/宿主组合上进行的研究清楚地表明，除了形态屏障外，RNA 干扰（RNAi）在阻止或允许分生组织入侵和垂直传播方面起着至关重要的作用。病毒在分生组织中与植物 RNAi 途径的相互作用对其症状、持久性、复制率以及最终进入宿主后代产生深远影响。
