Recent research has shown that plants can uptake long dsRNAs and dsRNA-derived siRNAs that target important genes of infecting fungi or viruses when applied on the surface of plant leaves. The external RNAs were capable of local and systemic movement inducing plant resistance against the pathogens. Few studies have been made for plant gene regulation by foliar application of RNAs. In this study, several types of ssRNA and siRNA duplexes targeting the neomycin phosphotransferase II (NPTII) transgene were in vitro-synthesized and externally applied to the leaf surface of 4-week-old transgenic Arabidopsis thaliana plants. External application of the synthetic NPTII-encoding siRNAs down-regulated NPTII transcript levels in transgenic A. thaliana 1 and 7 days post-treatment with a higher and more consistent effect being observed for siRNAs methylated at 3' ends. We also analyzed the effects of external NPTII-encoding dsRNA precursors and a dsRNA-derived heterogenous siRNA mix. Digestion of the NPTII-dsRNA to the heterogeneous siRNAs did not improve efficiency of the transgene suppression effect. Key Points• Foliar application of siRNAs down-regulated a commonly used transgene in Arabidopsis. • A more consistent effect was observed for methylated siRNAs. • The findings are important for development of plant gene regulation approaches.

中文翻译：

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通过叶面应用体外合成的小干扰RNA来抑制植物中的转基因。

最近的研究表明，将植物植物的叶片表面施用时，植物可以摄取长的dsRNA和dsRNA衍生的siRNA，这些siRNA靶向感染真菌或病毒的重要基因。外部RNA能够局部和全身运动，诱导植物对病原体的抗性。通过叶面应用RNA进行植物基因调控的研究很少。在这项研究中，体外合成了几种靶向新霉素磷酸转移酶II（NPTII）转基因的ssRNA和siRNA双链体，并将其外部施用于4周龄转基因拟南芥植物的叶表面。编码NPTII的合成siRNA的外部应用下调了转基因A中的NPTII转录水平。拟南芥治疗后1天和7天，对于在3'端甲基化的siRNA，观察到了更高且更一致的效果。我们还分析了外部NPTII编码dsRNA前体和dsRNA衍生的异源siRNA混合物的影响。将NPTII-dsRNA消化为异源siRNA并不能提高转基因抑制作用的效率。要点•siRNA的叶面应用下调了拟南芥中常用的转基因。•对于甲基化的siRNA，观察到更一致的效果。•这些发现对于开发植物基因调控方法很重要。将NPTII-dsRNA消化为异源siRNA并不能提高转基因抑制作用的效率。要点•siRNA的叶面应用下调了拟南芥中常用的转基因。•对于甲基化的siRNA，观察到更一致的效果。•这些发现对于开发植物基因调控方法很重要。将NPTII-dsRNA消化为异源siRNA并不能提高转基因抑制作用的效率。要点•siRNA的叶面应用下调了拟南芥中常用的转基因。•对于甲基化的siRNA，观察到更一致的效果。•这些发现对于开发植物基因调控方法很重要。