Successful subversion of translation initiation factors eIF4E determines the infection success of potyviruses, the largest group of viruses affecting plants. In the natural variability of many plant species, resistance to potyvirus infection is provided by polymorphisms at eIF4E that renders them inadequate for virus hijacking but still functional in translation initiation. In crops where such natural resistance alleles are limited, the genetic inactivation of eIF4E has been proposed for the engineering of potyvirus resistance. However, recent findings indicate that knockout eIF4E alleles may be deleterious for plant health and could jeopardize resistance efficiency in comparison to functional resistance proteins. Here, we explored the cause of these adverse effects by studying the role of the Arabidopsis eIF4E1, whose inactivation was previously reported as conferring resistance to the potyvirus clover yellow vein virus (ClYVV) while also promoting susceptibility to another potyvirus turnip mosaic virus (TuMV). We report that eIF4E1 is required to maintain global plant translation and to restrict TuMV accumulation during infection, and its absence is associated with a favoured virus multiplication over host translation. Furthermore, our findings show that, in the absence of eIF4E1, infection with TuMV results in the production of a truncated eIFiso4G1 protein. Finally, we demonstrate a role for eIFiso4G1 in TuMV accumulation and in supporting plant fitness during infection. These findings suggest that eIF4E1 counteracts the hijacking of the plant translational apparatus during TuMV infection and underscore the importance of preserving the functionality of translation initiation factors eIF4E when implementing potyvirus resistance strategies.

中文翻译：

---

拟南芥 eIF4E1 在 TuMV 感染期间保护翻译机制并限制病毒积累


翻译起始因子 eIF4E 的成功颠覆决定了马铃薯病毒属（影响植物的最大病毒群）的感染成功。在许多植物物种的自然变异中，对马铃薯Y病毒感染的抵抗力是由位点的多态性提供的。 eIF4E这使得它们不足以进行病毒劫持，但在翻译启动中仍然起作用。在此类天然抗性等位基因有限的作物中， eIF4E已提出用于马铃薯Y病毒抗性工程。然而，最近的研究结果表明，淘汰赛eIF4E与功能性抗性蛋白相比，等位基因可能对植物健康有害，并且可能危及抗性效率。在这里，我们通过研究这些不良影响的原因拟南芥eIF4E1此前曾报道，其失活可赋予对马铃薯Y病毒三叶草黄脉病毒（ClYVV）的抗性，同时还促进对另一种马铃薯Y病毒芜菁花叶病毒（TuMV）的易感性。我们报告说eIF4E1它是维持植物整体翻译和限制感染过程中TuMV积累所必需的，它的缺失与病毒比宿主翻译更有利的增殖有关。此外，我们的研究结果表明，在缺乏 eIF4E1 的情况下，TuMV 感染会导致产生截短的 eIFiso4G1 蛋白。最后，我们证明了 eIFiso4G1 在 TuMV 积累和感染期间支持植物适应性中的作用。 这些发现表明，eIF4E1 抵消了 TuMV 感染期间植物翻译装置的劫持，并强调了在实施马铃薯病毒抗性策略时保留翻译起始因子 eIF4E 功能的重要性。