• The Solanaceae family includes numerous highly valuable crops. Understanding the viral diseases that affect them is of great importance. Nicotiana benthamiana has contributed greatly to unravelling antiviral RNA interference, and can also be regarded as an adequate model for studying viral diseases of solanaceous crops. This species, however, as with many of its relatives, possesses an allopolyploid genome, in which homeologous gene pairs frequently occur.
• AGO1 is a pivotal component of most plant RNA silencing pathways. The Nicotiana benthamiana genome encodes two highly similar AGO1 homeologues: AGO1A and AGO1B. To understand their roles in planta, their genes were selectively inactivated. Given the inherent limitations of RNA interference‐based techniques, we used genome editing to achieve this goal.
• We found that AGO1A was not required for normal development, while AGO1B was indispensable for that. By contrast, the two homeologues both contributed to antiviral defence. Additionally, we observed that AGO1B utilised miR168 poorly, which may help to retain a significant level of antiviral RNA interference during viral infection.
• Our results have important implications for the better understanding of viral diseases of economically important solanaceous crops.

中文翻译：

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烟草本氏菌AGO1同源物的靶向失活揭示了它们在发育和抗病毒防御中的独特作用

• 该茄科家族包括许多非常有价值的作物。了解影响他们的病毒性疾病非常重要。烟草（Nicotiana benthamiana）为阐明抗病毒RNA干扰做出了巨大贡献，也可以被视为研究茄类作物病毒性疾病的合适模型。然而，该物种与其许多亲缘一样，拥有同素多倍体基因组，其中同源基因对经常发生。
• AGO1是大多数植物RNA沉默途径的关键组成部分。本氏烟草基因组编码两个高度相似的AGO1同源物：AGO1A和AGO1B。为了了解它们在植物中的作用，将其基因选择性失活。鉴于基于RNA干扰的技术固有的局限性，我们使用基因组编辑来实现此目标。
• 我们发现，AGO1A不是必需的正常发展，而AGO1B是对于不可缺少的。相比之下，这两个同源分子均有助于抗病毒防御。此外，我们观察到AGO1B对miR168的利用不佳，这可能有助于在病毒感染期间保持显着水平的抗病毒RNA干扰。
• 我们的结果对于更好地了解具有经济意义的茄类作物的病毒性疾病具有重要意义。