New Partnership for Africa's Development (NEPAD) Agency, Africa Biosafety Network of Expertise (ABNE), University of Ouagadougou, 06 BP 9884, Ouagadougou 06, Burkina Faso.
Transgenic Res. 2013 Dec;22(6):1073-88. doi: 10.1007/s11248-013-9728-1. Epub 2013 Jul 16.
A major application of RNA interference (RNAi) is envisaged for the production of virus-resistant transgenic plants. For fruit trees, this remains the most, if not the only, viable option for the control of plant viral disease outbreaks in cultivated orchards, due to the difficulties associated with the use of traditional and conventional disease-control measures. The use of RNAi might provide an additional benefit for woody crops if silenced rootstock can efficiently transmit the silencing signal to non-transformed scions, as has already been demonstrated in herbaceous plants. This would provide a great opportunity to produce non-transgenic fruit from transgenic rootstock. In this review, we scrutinise some of the concerns that might arise with the use of RNAi for engineering virus-resistant plants, and we speculate that this virus resistance has fewer biosafety concerns. This is mainly because RNAi-eliciting constructs only express small RNA molecules rather than proteins, and because this technology can be applied using plant rootstock that can confer virus resistance to the scion, leaving the scion untransformed. We discuss the main biosafety concerns related to the release of new types of virus-resistant plants and the risk assessment approaches in the application of existing regulatory systems (in particular, those of the European Union, the USA, and Canada) for the evaluation and approval of RNAi-mediated virus-resistant plants, either as transgenic varieties or as plant virus resistance induced by transgenic rootstock.
RNA 干扰 (RNAi) 的一个主要应用是生产抗病毒的转基因植物。对于果树来说，由于传统和常规疾病控制措施的使用存在困难，这仍然是控制果园中植物病毒病爆发的最可行（如果不是唯一可行）的选择。如果沉默的砧木能够有效地将沉默信号传递给未转化的接穗，就像在草本植物中已经证明的那样，那么 RNAi 的使用可能会为木本作物提供额外的好处。这将为从转基因砧木生产非转基因水果提供一个很好的机会。在这篇综述中，我们仔细研究了使用 RNAi 工程抗病毒植物可能引发的一些问题，并推测这种抗病毒方法的生物安全性问题较少。这主要是因为 RNAi 引发的构建体只表达小 RNA 分子而不是蛋白质，而且因为这项技术可以使用能够赋予接穗抗病毒能力的植物砧木来应用，而使接穗保持未转化状态。我们讨论了与释放新型抗病毒植物相关的主要生物安全问题，以及在应用现有监管系统（特别是欧盟、美国和加拿大的监管系统）评估和批准 RNAi 介导的抗病毒植物（无论是作为转基因品种还是作为转基因砧木诱导的植物病毒抗性）时的风险评估方法。
