Jilin Provincial Key Laboratory of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun, 130033, China.
Plant Cell Rep. 2018 Jan;37(1):103-114. doi: 10.1007/s00299-017-2186-0. Epub 2017 Jul 29.
Robust RNAi-mediated resistance to multiple Potyvirus strains and isolates, but not to Secovirus BPMV, was conferred by expressing a short SMV P3 hairpin in soybean plants. Engineering resistance to multiple Potyvirus strains is of great interest because of a wide variability of the virus strains, and mixed infections of multiple viruses or strains commonly associated with field grown soybean. In this study, RNAi-mediated silencing of the soybean mosaic virus (SMV) P3 cistron, which is reported to participate in virus movements and pathogenesis and to be the putative determinant of SMV virulence, was used to induce resistance to multiple Potyvirus strains and isolates in soybean. A 302 bp inverted repeat (IR) of the P3 cistron, isolated from the SMV strain SC3, was introduced into soybean. The transgenic lines exhibited stable and enhanced resistance to SMV SC3 under field conditions over 3 consecutive years. The transgenic lines also showed significantly enhanced resistance to four other SMV strains (SC7, SC15, SC18, and SMV-R, a novel recombinant found in China), the soybean-infecting bean common mosaic virus (BCMV) and watermelon mosaic virus (WMV). Nevertheless, no significant differences were found between transgenic plants and their non-transformed (NT) counterparts in terms of resistance to bean pod mottle virus (BPMV, Secoviridae). Consistent with the results of resistance evaluations, the expression of the respective viral CP cistrons and virus accumulation were significantly lower in seven Potyvirus strains and isolates than in the NT plants, but not in BCMV-inoculated transgenic lines. The results demonstrate the effectiveness of engineering resistance to multiple Potyvirus strains and isolates via RNAi-mediated SMV P3 cistron silencing, and thus provide an effective control strategy against Potyvirus infections in soybean and other crops.
在大豆植物中表达短的 SMV P3 发夹 RNA 可赋予对多种 Potyvirus 株系和分离物的稳健 RNAi 介导的抗性，但对 Secovirus BPMV 没有抗性。由于病毒株系的广泛变异性以及田间生长的大豆中常见的多种病毒或株系的混合感染，对多种 Potyvirus 株系的工程抗性具有很大的兴趣。在这项研究中，SMV P3 顺式元件的 RNAi 介导沉默被用来诱导大豆对多种 Potyvirus 株系和分离物的抗性，据报道，SMV P3 顺式元件参与病毒运动和发病机制，并被认为是 SMV 毒力的假定决定因素。从 SMV 株系 SC3 中分离出的 P3 顺式元件的 302bp 反向重复（IR）被导入大豆中。在田间条件下，经过连续 3 年，转基因系表现出对 SMV SC3 的稳定和增强抗性。转基因系还表现出对其他 4 种 SMV 株系（SC7、SC15、SC18 和在中国发现的新型重组体 SMV-R）、大豆侵染的豆普通花叶病毒（BCMV）和西瓜花叶病毒（WMV）的显著增强抗性。然而，在对豆荚斑驳病毒（BPMV，属于正呼肠孤病毒科）的抗性方面，转基因植株与未转化（NT）植株之间没有发现显著差异。与抗性评估结果一致，在 7 种 Potyvirus 株系和分离物中，与 NT 植物相比，各自的病毒 CP 顺式元件的表达和病毒积累显著降低，但在 BCMV 接种的转基因系中没有降低。结果表明，通过 RNAi 介导的 SMV P3 顺式元件沉默来工程抗性对多种 Potyvirus 株系和分离物是有效的，因此为防治大豆和其他作物中的 Potyvirus 感染提供了一种有效的控制策略。
