In some plant–virus interactions plants show a sign of healing from virus infection, a phenomenon called symptom recovery. It is assumed that the meristem exclusion of the virus is essential to this process. The discovery of RNA silencing provided a possible mechanism to explain meristem exclusion and recovery. Here we show evidence that silencing is not the reason for meristem exclusion in Nicotiana benthamiana plants infected with Cymbidium ringspot virus (CymRSV). Transcriptome analysis followed by in situ hybridization shed light on the changes in gene expression in the shoot apical meristem (SAM) on virus infection. We observed the down‐regulation of meristem‐specific genes, including WUSCHEL (WUS). However, WUS was not down‐regulated in the SAM of plants infected with meristem‐invading viruses such as turnip vein‐clearing virus (TVCV) and cucumber mosaic virus (CMV). Moreover, there is no connection between loss of meristem function and fast shoot necrosis since TVCV necrotized the shoot while CMV did not. Our findings suggest that the observed transcriptional changes on virus infection in the shoot are key factors in tip necrosis and symptom recovery. We observed a lack of GLYCERALDEHYDE 3-PHOSPHATE DEHYDROGENASE (GAPDH) expression in tissues around the meristem, which likely stops virus replication and spread into the meristem.

中文翻译：

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感染 CymRSV 的本塞姆氏烟草植物的茎尖分生组织中的转录组重编程与病毒排除和缺乏恢复有关。


在一些植物与病毒的相互作用中，植物表现出从病毒感染中恢复的迹象，这种现象称为症状恢复。据认为，病毒的分生组织排除对此过程至关重要。 RNA沉默的发现提供了解释分生组织排除和恢复的可能机制。在这里，我们证明沉默并不是感染蕙兰环斑病毒（CymRSV）的本塞姆氏烟草植物中分生组织排斥的原因。转录组分析和原位杂交揭示了病毒感染时茎尖分生组织（SAM）基因表达的变化。我们观察到分生组织特异性基因的下调，包括WUSCHEL ( WUS )。然而，在感染分生组织入侵病毒（例如萝卜静脉清除病毒（TVCV）和黄瓜花叶病毒（CMV））的植物的 SAM 中， WUS并未下调。此外，分生组织功能丧失与芽快速坏死之间没有联系，因为 TVCV 使芽坏死，而 CMV 则不然。我们的研究结果表明，观察到的芽中病毒感染的转录变化是尖端坏死和症状恢复的关键因素。我们观察到分生组织周围的组织中缺乏甘油醛3-磷酸脱氢酶（ GAPDH ）表达，这可能会阻止病毒复制并扩散到分生组织中。