Abstract

Many members of the family Gesneriaceae are cultivated as ornamental plants, including Cape primrose (Streptocarpus) species. The range of plant architecture found in this genus has also made it a model to study leaf and meristem development and their evolution. However, the lack of tools to study gene functions through reverse genetics in Streptocarpus has limited the exploitation of its genetic potential. To aid functional genomic studies in Streptocarpus rexii, we sought to investigate virus-induced gene silencing (VIGS). Using the broad host range Tobacco Rattle Virus (TRV) to target the PHYTOENE DESATURASE (PDS) gene of S. rexii, we show that infection with sap from Nicotiana benthamiana triggered VIGS efficiently. VIGS was most effective in the seedling leaves 8 weeks after sowing, but was limited in duration and systemic spread. This study reports the first successful use of VIGS in Streptocarpus and in the family Gesneriaceae. The inoculation of viral sap derived from N. benthamiana was able to overcome the difficulties of standard Agrobacterium-mediated transformation in this genus. Irrespective of its transient effect, this VIGS system will be useful to assess gene function at the cellular level and represent an important tool for further understanding molecular mechanisms in Streptocarpus.

中文翻译：

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Streptocarpus rexii（苦苣苔科）中病毒诱导的基因沉默。

 抽象的

苦苣苔科的许多成员都被栽培为观赏植物，其中包括海角报春花 ( Streptocarpus ) 物种。该属中发现的植物结构范围也使其成为研究叶子和分生组织发育及其进化的模型。然而，缺乏通过反向遗传学研究链果属基因功能的工具限制了其遗传潜力的开发。为了帮助对霸王龙的功能基因组研究，我们试图研究病毒诱导的基因沉默（VIGS）。利用广泛宿主范围的烟草脆裂病毒 (TRV) 来靶向霸王龙的PHYTOENE 去饱和酶 ( PDS ) 基因，我们发现烟草本塞姆氏 ( Nicotiana Benthamiana)的汁液感染可有效触发 VIGS。 VIGS 在播种后 8 周的幼苗叶片中最为有效，但持续时间和系统性传播有限。这项研究报告了 VIGS 首次在链果属和苦苣苔科中的成功应用。接种源自本塞姆氏烟草的病毒汁液能够克服该属中标准农杆菌介导的转化的困难。无论其瞬时效应如何，该 VIGS 系统将有助于评估细胞水平的基因功能，并成为进一步了解链果属分子机制的重要工具。