Table_2_Functional Analysis of RNA Interference-Related Soybean Pod Borer (Lepidoptera) Genes Based on Transcriptome Sequences.DOCX

RNA interference (RNAi) is useful for controlling pests of agriculturally important crops. The soybean pod borer (SPB) is the most important soybean pest in Northeastern Asia. In an earlier study, we confirmed that the SPB could be controlled via transgenic plant-mediated RNAi. Here, the SPB transcriptome was sequenced to identify RNAi-related genes, and also to establish an RNAi-of-RNAi assay system for evaluating genes involved in the SPB systemic RNAi response. The core RNAi genes, as well as genes potentially involved in double-stranded RNA (dsRNA) uptake were identified based on SPB transcriptome sequences. A phylogenetic analysis and the characterization of these core components as well as dsRNA uptake related genes revealed that they contain conserved domains essential for the RNAi pathway. The results of the RNAi-of-RNAi assay involving Laccase 2 (a critical cuticle pigmentation gene) as a marker showed that genes encoding the sid-like (Sil1), scavenger receptor class C (Src), and scavenger receptor class B (Srb3 and Srb4) proteins of the endocytic pathway were required for SPB cellular uptake of dsRNA. The SPB response was inferred to contain three functional small RNA pathways (i.e., miRNA, siRNA, and piRNA pathways). Additionally, the SPB systemic RNA response may rely on systemic RNA interference deficient transmembrane channel-mediated and receptor-mediated endocytic pathways. The results presented herein may be useful for developing RNAi-mediated methods to control SPB infestations in soybean.

RNA干扰（RNA interference，RNAi）可用于防控具有重要农业经济价值的作物害虫。大豆荚螟（soybean pod borer，SPB）是东北亚地区最主要的大豆害虫。在此前的一项研究中，我们已证实可通过转基因植物介导的RNA干扰防控大豆荚螟。本研究通过对大豆荚螟转录组进行测序，以鉴定与RNA干扰相关的基因，并建立“RNA干扰靶向RNA干扰（RNAi-of-RNAi）”检测体系，用于评估参与大豆荚螟系统性RNA干扰应答的基因。基于大豆荚螟转录组序列，我们鉴定出了核心RNA干扰基因，以及潜在参与双链RNA（double-stranded RNA，dsRNA）摄取的基因。对这些核心组分及双链RNA摄取相关基因进行的系统发育分析与功能表征显示，它们包含RNA干扰通路所必需的保守结构域。以漆酶2（Laccase 2，一种关键的表皮色素沉着基因）作为标记物的RNAi-of-RNAi检测结果显示，编码内吞通路中类sid蛋白（Sil1）、C型清道夫受体（Src）以及B型清道夫受体（Srb3与Srb4）的基因，是大豆荚螟细胞摄取双链RNA所必需的。研究推断大豆荚螟的RNA干扰应答包含三条功能性小RNA通路，即微小RNA（microRNA，miRNA）通路、小干扰RNA（small interfering RNA，siRNA）通路以及PIWI相互作用RNA（PIWI-interacting RNA，piRNA）通路。此外，大豆荚螟的系统性RNA干扰应答可能依赖于系统性RNA干扰缺陷型跨膜通道介导以及受体介导的内吞通路。本研究所得结果可为开发基于RNA干扰的大豆荚螟虫害防控方法提供参考。